diff --git a/README.md b/README.md
index c7d50dd..ec8c82e 100644
--- a/README.md
+++ b/README.md
@@ -2,8 +2,8 @@
 #Kundenkarten Analyse
 
 [![Build Status](https://teamcity.joethei.xyz/app/rest/builds/buildType:(id:Studium_Programmierung_Softwareprojektmanagement_SpmProd)/statusIcon)](https://tcstatus.joethei.space/dashboard/spm)
-[![Quality Gate](https://sonarqube.joethei.xyz/api/project_badges/measure?project=Studium_Programmierung_Softwareprojektmanagement&metric=alert_status)
-![Code Coverage](https://sonarqube.joethei.xyz/api/project_badges/measure?project=Studium_Programmierung_Softwareprojektmanagement&metric=coverage)](https://sonarqube.joethei.xyz/dashboard?id=Studium_Programmierung_Softwareprojektmanagement)
+[![Quality Gate Status](https://sonarqube.joethei.xyz/api/project_badges/measure?project=de.hs-el.spm%3AbauDas-kundenkarten&metric=alert_status)](https://sonarqube.joethei.xyz/dashboard?id=de.hs-el.spm%3AbauDas-kundenkarten)
+
 
 ## minimal Requirements
 
diff --git a/src/main/java/de/hsel/spm/baudas/analysis/Analysis.java b/src/main/java/de/hsel/spm/baudas/analysis/Analysis.java
index 3723996..e91a931 100644
--- a/src/main/java/de/hsel/spm/baudas/analysis/Analysis.java
+++ b/src/main/java/de/hsel/spm/baudas/analysis/Analysis.java
@@ -6,6 +6,7 @@ import weka.core.converters.CSVLoader;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.logging.Logger;
 
 /**
  * base interface for analysis.
@@ -31,7 +32,7 @@ public interface Analysis<T> {
             loader.setSource(file);
             return loader.getDataSet();
         } catch (IOException e) {
-            e.printStackTrace();
+            Logger.getLogger("BauDas").throwing(this.getClass().getName(), "load", e);
         }
         return null;
     }
diff --git a/src/main/java/de/hsel/spm/baudas/analysis/Attribute.java b/src/main/java/de/hsel/spm/baudas/analysis/Attribute.java
index 9d29e36..08558a2 100644
--- a/src/main/java/de/hsel/spm/baudas/analysis/Attribute.java
+++ b/src/main/java/de/hsel/spm/baudas/analysis/Attribute.java
@@ -37,5 +37,7 @@ class Attribute {
     static final int GARDENING_TOOLS = 25;
 
 
+    private Attribute() {
 
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/de/hsel/spm/baudas/analysis/Cluster.java b/src/main/java/de/hsel/spm/baudas/analysis/Cluster.java
index 0608bd7..d5d974e 100644
--- a/src/main/java/de/hsel/spm/baudas/analysis/Cluster.java
+++ b/src/main/java/de/hsel/spm/baudas/analysis/Cluster.java
@@ -9,6 +9,7 @@ import weka.filters.unsupervised.attribute.Remove;
 import java.io.File;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.logging.Logger;
 
 /**
  * Cluster Analysis.
@@ -46,7 +47,7 @@ public class Cluster implements Analysis<Map<Integer, Map<String, String>>> {
             remove.setInputFormat(instances);
             instances = Filter.useFilter(instances, remove);
         } catch (Exception e) {
-            e.printStackTrace();
+            Logger.getLogger("BauDas").throwing(this.getClass().getName(), "getResult", e);
         }
 
         //creating a single cluster to get average, weka has no way to get that from a bigger one.
@@ -59,7 +60,7 @@ public class Cluster implements Analysis<Map<Integer, Map<String, String>>> {
             averageCentroids = averageMeans.getClusterCentroids();
 
         } catch (Exception ex) {
-            ex.printStackTrace();
+            Logger.getLogger("BauDas").throwing(this.getClass().getName(), "getResult", ex);
         }
         assert averageCentroids != null;
 
@@ -77,7 +78,7 @@ public class Cluster implements Analysis<Map<Integer, Map<String, String>>> {
             putIntoMap(centroids, count);
 
         } catch (Exception ex) {
-            ex.printStackTrace();
+            Logger.getLogger("BauDas").throwing(this.getClass().getName(), "getResult", ex);
         }
         return result;
     }
diff --git a/src/main/java/de/hsel/spm/baudas/analysis/ShoppingCart.java b/src/main/java/de/hsel/spm/baudas/analysis/ShoppingCart.java
index f1277e1..da437e9 100644
--- a/src/main/java/de/hsel/spm/baudas/analysis/ShoppingCart.java
+++ b/src/main/java/de/hsel/spm/baudas/analysis/ShoppingCart.java
@@ -13,6 +13,7 @@ import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.logging.Logger;
 
 /**
  * The shopping-cart analysis.
@@ -45,7 +46,7 @@ public class ShoppingCart implements Analysis<Map<List<String>, List<String>>> {
             nc.setInputFormat(instances);
             instances = Filter.useFilter(instances, nc);
         } catch (Exception e) {
-            e.printStackTrace();
+            Logger.getLogger("BauDas").throwing(this.getClass().getName(), "getResult", e);
         }
 
 
@@ -55,7 +56,7 @@ public class ShoppingCart implements Analysis<Map<List<String>, List<String>>> {
             num2nom.setInputFormat(instances);
             instances = Filter.useFilter(instances, num2nom);
         } catch (Exception e) {
-            e.printStackTrace();
+            Logger.getLogger("BauDas").throwing(this.getClass().getName(), "getResult", e);
         }
 
         Apriori model = new Apriori();
@@ -64,7 +65,7 @@ public class ShoppingCart implements Analysis<Map<List<String>, List<String>>> {
         try {
             model.buildAssociations(instances);
         } catch (Exception e) {
-            e.printStackTrace();
+            Logger.getLogger("BauDas").throwing(this.getClass().getName(), "getResult", e);
         }
 
         for (int i = 0; i < model.getAssociationRules().getRules().size(); i++) {
diff --git a/src/main/java/de/hsel/spm/baudas/analysis/WeekOverview.java b/src/main/java/de/hsel/spm/baudas/analysis/WeekOverview.java
index ee3dd19..f70bd45 100644
--- a/src/main/java/de/hsel/spm/baudas/analysis/WeekOverview.java
+++ b/src/main/java/de/hsel/spm/baudas/analysis/WeekOverview.java
@@ -21,7 +21,6 @@ public class WeekOverview implements Analysis<Map<String, Map.Entry<Double, Inte
     private Map<String, Map.Entry<Double, Integer>> result;
 
     public WeekOverview(File file) {
-
         instances = load(file);
     }
 
diff --git a/src/main/java/de/hsel/spm/baudas/web/AuthorizationFilter.java b/src/main/java/de/hsel/spm/baudas/web/AuthorizationFilter.java
index 6d0b81c..c30d696 100644
--- a/src/main/java/de/hsel/spm/baudas/web/AuthorizationFilter.java
+++ b/src/main/java/de/hsel/spm/baudas/web/AuthorizationFilter.java
@@ -32,10 +32,9 @@ public class AuthorizationFilter implements Filter {
      * initialize this filter.
      *
      * @param filterConfig configuration
-     * @throws ServletException failed to initialize filter
      */
     @Override
-    public void init(@NotNull FilterConfig filterConfig) throws ServletException {
+    public void init(@NotNull FilterConfig filterConfig) {
         this.context = filterConfig.getServletContext();
         this.context.log("AuthorizationFilter initialized");
     }
diff --git a/src/main/java/de/hsel/spm/baudas/web/DatasetManagement.java b/src/main/java/de/hsel/spm/baudas/web/DatasetManagement.java
index 5cd4f69..95db76d 100644
--- a/src/main/java/de/hsel/spm/baudas/web/DatasetManagement.java
+++ b/src/main/java/de/hsel/spm/baudas/web/DatasetManagement.java
@@ -16,6 +16,8 @@ import java.util.List;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
+import java.util.logging.Logger;
+import java.util.stream.Stream;
 
 /**
  * manages data about .csv files.
@@ -45,8 +47,10 @@ public class DatasetManagement {
 
         if (files.get(session).size() >= 5) {
             SavedFile file = files.get(session).iterator().next();
-            if (!get(file.getUuid()).delete()) {
-                System.err.println("failed to delete file " + file);
+            try {
+                Files.delete(get(file.getUuid()).toPath());
+            } catch (IOException e) {
+                Logger.getLogger("BauDas").throwing(DatasetManagement.class.getName(), "add", e);
             }
             files.get(session).remove(file);
         }
@@ -63,16 +67,19 @@ public class DatasetManagement {
         if (!files.containsKey(session)) return;
 
         for (SavedFile file : files.get(session)) {
-            if (!get(file.getUuid()).delete())
-                System.err.println("failed to delete file " + file);
+            try {
+                Files.delete(get(file.getUuid()).toPath());
+            } catch (IOException e) {
+                Logger.getLogger("BauDas").throwing(DatasetManagement.class.getName(), "delete", e);
+            }
         }
         files.remove(session);
 
         //deleting all files older than x days.
         int days = 30;
 
-        try {
-            Files.list(Paths.get("")).forEach(path -> {
+        try (Stream<Path> stream = Files.list(Paths.get(""))) {
+            stream.forEach(path -> {
                 if (path.toFile().getName().endsWith("*.csv")) {
                     long diff = new Date().getTime() - path.toFile().lastModified();
 
@@ -80,13 +87,13 @@ public class DatasetManagement {
                         try {
                             Files.delete(path);
                         } catch (IOException e) {
-                            e.printStackTrace();
+                            Logger.getLogger("BauDas").throwing(DatasetManagement.class.getName(), "delete", e);
                         }
                     }
                 }
             });
         } catch (IOException ex) {
-            ex.printStackTrace();
+            Logger.getLogger("BauDas").throwing(DatasetManagement.class.getName(), "delete", ex);
         }
     }
 
@@ -113,4 +120,7 @@ public class DatasetManagement {
     private static String getFileName(@NotNull UUID uuid) {
         return uuid + ".csv";
     }
+
+    private DatasetManagement() {
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/de/hsel/spm/baudas/web/ErrorCode.java b/src/main/java/de/hsel/spm/baudas/web/ErrorCode.java
index c293349..c5ff4ff 100644
--- a/src/main/java/de/hsel/spm/baudas/web/ErrorCode.java
+++ b/src/main/java/de/hsel/spm/baudas/web/ErrorCode.java
@@ -27,7 +27,6 @@ public enum ErrorCode {
      */
     public static boolean exists(String message) {
         for (ErrorCode code : values()) {
-            System.out.println(message + " == " + code.name());
             if (code.name().equals(message))
                 return true;
         }
diff --git a/src/main/java/de/hsel/spm/baudas/web/LoginServlet.java b/src/main/java/de/hsel/spm/baudas/web/LoginServlet.java
index de96b79..83baa02 100644
--- a/src/main/java/de/hsel/spm/baudas/web/LoginServlet.java
+++ b/src/main/java/de/hsel/spm/baudas/web/LoginServlet.java
@@ -32,6 +32,7 @@ public class LoginServlet extends HttpServlet {
      * @param response response object
      * @throws IOException failed to initialize print writer
      */
+    @Override
     protected void doPost(@NotNull HttpServletRequest request, @NotNull HttpServletResponse response) throws ServletException, IOException {
         String password = request.getParameter("password");
         if (this.password.equals(password)) {
diff --git a/src/main/java/de/hsel/spm/baudas/web/LogoutServlet.java b/src/main/java/de/hsel/spm/baudas/web/LogoutServlet.java
index 302c2ca..c1c914a 100644
--- a/src/main/java/de/hsel/spm/baudas/web/LogoutServlet.java
+++ b/src/main/java/de/hsel/spm/baudas/web/LogoutServlet.java
@@ -27,6 +27,7 @@ public class LogoutServlet extends HttpServlet {
      * @param response response object
      * @throws IOException failed to initialize print writer
      */
+    @Override
     protected void doGet(@NotNull HttpServletRequest request, @NotNull HttpServletResponse response) throws IOException {
         HttpSession session = request.getSession();
         if (session != null) {
diff --git a/src/main/java/de/hsel/spm/baudas/web/UploadServlet.java b/src/main/java/de/hsel/spm/baudas/web/UploadServlet.java
index 9616b2c..747a632 100644
--- a/src/main/java/de/hsel/spm/baudas/web/UploadServlet.java
+++ b/src/main/java/de/hsel/spm/baudas/web/UploadServlet.java
@@ -17,6 +17,7 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.nio.file.StandardCopyOption;
+import java.util.logging.Logger;
 
 /**
  * saves uploaded files.
@@ -62,45 +63,59 @@ public class UploadServlet extends HttpServlet {
         Part filePart = req.getPart("file");
 
         if (filePart == null) {
-            resp.sendRedirect("error.jsp?code=" + ErrorCode.FILE_NOT_FOUND);
+            error(resp, ErrorCode.FILE_NOT_FOUND);
             return;
         }
 
         if (filePart.getSubmittedFileName() == null) {
-            resp.sendRedirect("error.jsp?code=" + ErrorCode.FILE_NOT_FOUND);
+            error(resp, ErrorCode.FILE_NOT_FOUND);
             return;
         }
 
         String fileName = Paths.get(filePart.getSubmittedFileName()).getFileName().toString();
 
         if (fileName == null) {
-            resp.sendRedirect("error.jsp?code=" + ErrorCode.FILE_NOT_FOUND);
+            error(resp, ErrorCode.FILE_NOT_FOUND);
             return;
         }
 
         InputStream inputStream = filePart.getInputStream();
 
         if (inputStream == null) {
-            resp.sendRedirect("error.jsp?code=" + ErrorCode.FILE_NOT_FOUND);
+            error(resp, ErrorCode.FILE_NOT_FOUND);
             return;
         }
         if (inputStream.available() == 0) {
-            resp.sendRedirect("error.jsp?code=" + ErrorCode.EMPTY_FILE);
+            error(resp, ErrorCode.EMPTY_FILE);
             return;
         }
 
         if (!checkFormat(inputStream)) {
-            resp.sendRedirect("error.jsp?code=" + ErrorCode.INVALID_FORMAT);
+            error(resp, ErrorCode.INVALID_FORMAT);
             return;
         } else {
             inputStream = filePart.getInputStream();
         }
 
         Path path = DatasetManagement.add(fileName, req.getSession().getId());
-        if (!Files.exists(path)) {
+        if (!path.toFile().exists()) {
             Files.createFile(path);
         }
 
         Files.copy(inputStream, path, StandardCopyOption.REPLACE_EXISTING);
     }
+
+    /**
+     * redirect to error page.
+     *
+     * @param response response object
+     * @param code error code
+     */
+    private void error(@NotNull HttpServletResponse response, @NotNull ErrorCode code) {
+        try {
+            response.sendRedirect("error.jsp?code=" + code);
+        } catch (IOException e) {
+            Logger.getLogger("BauDas").throwing(getClass().getName(), "error", e);
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/de/hsel/spm/baudas/web/depiction/ClusterTable.java b/src/main/java/de/hsel/spm/baudas/web/depiction/ClusterTable.java
index aa3afb5..242cfc5 100644
--- a/src/main/java/de/hsel/spm/baudas/web/depiction/ClusterTable.java
+++ b/src/main/java/de/hsel/spm/baudas/web/depiction/ClusterTable.java
@@ -26,7 +26,7 @@ import java.util.UUID;
 @WebServlet("/clusters")
 public class ClusterTable extends HttpServlet implements Depiction {
 
-    private static Map<UUID, Map> cache;
+    private static Map<UUID, Map> cache = new HashMap<>();
 
     /**
      * returns formatted analysis result to HTTP GET request from supplied id.
@@ -37,15 +37,14 @@ public class ClusterTable extends HttpServlet implements Depiction {
      */
     @Override
     protected void doGet(@NotNull HttpServletRequest req, @NotNull HttpServletResponse resp) throws IOException {
-        UUID uuid = setup(req, resp, cache);
+        UUID uuid = init(req, resp, cache);
         if (uuid == null) return;
 
 
-        Map<Integer, Map<String, String>> result = new HashMap<>();
         File file = DatasetManagement.get(uuid);
 
         Cluster cluster = new Cluster(file);
-        result = cluster.getResult();
+        Map<Integer, Map<String, String>> result = cluster.getResult();
 
         PrintWriter out = resp.getWriter();
         Gson gson = new Gson();
diff --git a/src/main/java/de/hsel/spm/baudas/web/depiction/Depiction.java b/src/main/java/de/hsel/spm/baudas/web/depiction/Depiction.java
index edca3ce..070edbd 100644
--- a/src/main/java/de/hsel/spm/baudas/web/depiction/Depiction.java
+++ b/src/main/java/de/hsel/spm/baudas/web/depiction/Depiction.java
@@ -11,6 +11,7 @@ import java.io.PrintWriter;
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.util.UUID;
+import java.util.logging.Logger;
 import java.util.regex.Pattern;
 
 /**
@@ -31,7 +32,7 @@ interface Depiction {
      * @return validated uuid
      */
     @Nullable
-    default UUID setup(@NotNull HttpServletRequest request, @NotNull HttpServletResponse response, @NotNull Map<UUID, Map> cache) {
+    default UUID init(@NotNull HttpServletRequest request, @NotNull HttpServletResponse response, @NotNull Map<UUID, Map> cache) {
         try {
             request.setCharacterEncoding(StandardCharsets.UTF_8.name());
             response.setCharacterEncoding(StandardCharsets.UTF_8.name());
@@ -50,7 +51,7 @@ interface Depiction {
             }
             return uuid;
         } catch (IOException e) {
-            e.printStackTrace();
+            Logger.getLogger("BauDas").throwing(this.getClass().getName(), "init", e);
         }
         return null;
     }
diff --git a/src/main/java/de/hsel/spm/baudas/web/depiction/SalesNumberChart.java b/src/main/java/de/hsel/spm/baudas/web/depiction/SalesNumberChart.java
index 24eba0e..28d92f4 100644
--- a/src/main/java/de/hsel/spm/baudas/web/depiction/SalesNumberChart.java
+++ b/src/main/java/de/hsel/spm/baudas/web/depiction/SalesNumberChart.java
@@ -42,7 +42,7 @@ public class SalesNumberChart extends HttpServlet implements Depiction {
      */
     @Override
     protected void doGet(@NotNull HttpServletRequest req, @NotNull HttpServletResponse resp) throws IOException {
-        UUID uuid = setup(req, resp, cache);
+        UUID uuid = init(req, resp, cache);
         if (uuid == null) return;
 
         File file = DatasetManagement.get(uuid);
diff --git a/src/main/java/de/hsel/spm/baudas/web/depiction/ShoppingCartTable.java b/src/main/java/de/hsel/spm/baudas/web/depiction/ShoppingCartTable.java
index 311df27..9013ca6 100644
--- a/src/main/java/de/hsel/spm/baudas/web/depiction/ShoppingCartTable.java
+++ b/src/main/java/de/hsel/spm/baudas/web/depiction/ShoppingCartTable.java
@@ -31,7 +31,7 @@ public class ShoppingCartTable extends HttpServlet implements Depiction {
 
     private static final long serialVersionUID = 5026732432605473505L;
 
-    private static Map<UUID, Map> cache;
+    private static Map<UUID, Map> cache = new HashMap<>();
 
     /**
      * returns formatted analysis result to HTTP GET request from supplied id.
@@ -40,8 +40,9 @@ public class ShoppingCartTable extends HttpServlet implements Depiction {
      * @param resp response object
      * @throws IOException failed to initialize print writer
      */
+    @Override
     protected void doGet(@NotNull HttpServletRequest req, @NotNull HttpServletResponse resp) throws IOException {
-        UUID uuid = setup(req, resp, cache);
+        UUID uuid = init(req, resp, cache);
         if (uuid == null) return;
 
 
diff --git a/src/main/java/de/hsel/spm/baudas/web/depiction/ShoppingTimesChart.java b/src/main/java/de/hsel/spm/baudas/web/depiction/ShoppingTimesChart.java
index 615bf57..9ee5fdd 100644
--- a/src/main/java/de/hsel/spm/baudas/web/depiction/ShoppingTimesChart.java
+++ b/src/main/java/de/hsel/spm/baudas/web/depiction/ShoppingTimesChart.java
@@ -47,7 +47,7 @@ public class ShoppingTimesChart extends HttpServlet implements Depiction {
      */
     @Override
     protected void doGet(@NotNull HttpServletRequest req, @NotNull HttpServletResponse resp) throws IOException {
-        UUID uuid = setup(req, resp, cache);
+        UUID uuid = init(req, resp, cache);
         if (uuid == null) return;
 
 
diff --git a/src/main/java/de/hsel/spm/baudas/web/depiction/WeekOverviewChart.java b/src/main/java/de/hsel/spm/baudas/web/depiction/WeekOverviewChart.java
index d9d0cb0..55d258a 100644
--- a/src/main/java/de/hsel/spm/baudas/web/depiction/WeekOverviewChart.java
+++ b/src/main/java/de/hsel/spm/baudas/web/depiction/WeekOverviewChart.java
@@ -44,7 +44,7 @@ public class WeekOverviewChart extends HttpServlet implements Depiction {
 
     @Override
     protected void doGet(@NotNull HttpServletRequest req, @NotNull HttpServletResponse resp) throws IOException {
-        UUID uuid = setup(req, resp, cache);
+        UUID uuid = init(req, resp, cache);
 
         if (uuid == null) return;
 
diff --git a/src/main/webapp/js/clusters.js b/src/main/webapp/js/clusters.js
index a255cc6..ac9709f 100644
--- a/src/main/webapp/js/clusters.js
+++ b/src/main/webapp/js/clusters.js
@@ -1,30 +1,38 @@
+/**
+ * renders cluster analysis results as a table.
+ *
+ * @author Julian Hinxlage
+ * @version 0.1
+ * @since 1.0
+ */
+
 let cluster_result;
 
 function updateClusters(id) {
-    if(typeof id !== 'undefined') {
+    if (typeof id !== 'undefined') {
         request('clusters', id).then(function (data) {
             cluster_result = data;
             drawClusterTable();
         });
-    }else request('clusters').then(function(data) {
+    } else request('clusters').then(function (data) {
         cluster_result = data;
         drawClusterTable();
     });
 }
 
-function drawClusterTable(){
+function drawClusterTable() {
     let table = document.getElementById("cluster_table");
-    while(table.hasChildNodes()){
+    while (table.hasChildNodes()) {
         table.removeChild(table.firstChild);
     }
 
     let row = $("<thead>");
     row.append("<tr>");
     row.append("<td></td>");
-    for (x in cluster_result){
-        if(x == 0){
+    for (let x in cluster_result) {
+        if (x == 0) {
             row.append("<td>" + "Durchschnitt" + "</td>");
-        }else{
+        } else {
             row.append("<td>" + x + "</td>");
         }
     }
@@ -44,12 +52,12 @@ function drawClusterTable(){
     $("#cluster_table").append(row);
 }
 
-function appendClusterTable(row, attrib){
+function appendClusterTable(row, attrib) {
     row.append("</tbody>");
     row.append("<tr>");
     row.append("<td>" + attrib + "</td>");
-    for (x in cluster_result){
-        row.append($("<td>" + cluster_result[x][attrib] +"</td>"));
+    for (let x in cluster_result) {
+        row.append($("<td>" + cluster_result[x][attrib] + "</td>"));
     }
     row.append("</tr>");
 }
diff --git a/src/main/webapp/js/cache.js b/src/main/webapp/js/datasets.js
similarity index 96%
rename from src/main/webapp/js/cache.js
rename to src/main/webapp/js/datasets.js
index e474c4b..904b7f5 100644
--- a/src/main/webapp/js/cache.js
+++ b/src/main/webapp/js/datasets.js
@@ -1,3 +1,11 @@
+/**
+ * Dataset switching and listing.
+ *
+ * @author Johannes Theiner
+ * @version 0.1
+ * @since 1.0
+ */
+
 
 Chart.defaults.global.defaultFontColor = "black";
 
diff --git a/src/main/webapp/js/sales.js b/src/main/webapp/js/sales.js
index 995a428..a506b62 100644
--- a/src/main/webapp/js/sales.js
+++ b/src/main/webapp/js/sales.js
@@ -1,3 +1,11 @@
+/**
+ * renders sales numbers as chart.
+ *
+ * @author Johannes Theiner
+ * @version 0.1
+ * @since 1.0
+ */
+
 let top_flop_result;
 
 
@@ -13,8 +21,7 @@ let sales = new Chart($("#sales_chart"), {
     options: {
         responsive: true,
         title: {
-            display: false,
-            text: 'Top Flop Artikel'
+            display: false
         },
         legend: {
             display: false
diff --git a/src/main/webapp/js/shopping_cart.js b/src/main/webapp/js/shopping_cart.js
index 70b7bb5..8dbcbc6 100644
--- a/src/main/webapp/js/shopping_cart.js
+++ b/src/main/webapp/js/shopping_cart.js
@@ -1,3 +1,11 @@
+/**
+ * renders shopping cart analysis results as a table.
+ *
+ * @author Karsten Eden
+ * @version 0.1
+ * @since 1.0
+ */
+
 let shopping_cart_result;
 
 function updateShoppingCartTable(id) {
@@ -25,7 +33,7 @@ function drawShoppingCartTable(){
     row.append("</tr>");
     row.append("</thead>");
     row.append("<tbody>");
-    for (x in shopping_cart_result){
+    for (let x in shopping_cart_result){
         row.append("<tr>");
         row.append("<td>" + shopping_cart_result[x].key + "</td>");
         row.append("<td>" + shopping_cart_result[x].value + "</td>");
diff --git a/src/main/webapp/js/shopping_times.js b/src/main/webapp/js/shopping_times.js
index 1f29752..e13c90b 100644
--- a/src/main/webapp/js/shopping_times.js
+++ b/src/main/webapp/js/shopping_times.js
@@ -1,3 +1,11 @@
+/**
+ * renders shopping times analysis result as chart with day selection.
+ *
+ * @author Johannes Theiner
+ * @version 0.1
+ * @since 1.0
+ */
+
 let shopping_result;
 
 let shopping_chart = new Chart(document.getElementById("shopping_times_chart"), {
diff --git a/src/main/webapp/js/upload.js b/src/main/webapp/js/upload.js
index 11d344d..4c50324 100644
--- a/src/main/webapp/js/upload.js
+++ b/src/main/webapp/js/upload.js
@@ -1,3 +1,11 @@
+/**
+ * upload files and show loading modal
+ *
+ * @author Johannes Theiner
+ * @version 0.1
+ * @since 1.0
+ */
+
 let form = document.getElementById("upload");
 
 form.onsubmit = function (event) {
@@ -12,7 +20,7 @@ form.onsubmit = function (event) {
         loading.removeClass("hide");
         $('.sidenav').sidenav('close');
         loading.modal('open');
-    }
+    };
 
     xhr.upload.addEventListener("progress", function (event) {
         if (event.lengthComputable) {
diff --git a/src/main/webapp/js/week_overview.js b/src/main/webapp/js/week_overview.js
index c20f5b7..72198bf 100644
--- a/src/main/webapp/js/week_overview.js
+++ b/src/main/webapp/js/week_overview.js
@@ -1,3 +1,11 @@
+/**
+ * render week overview analysis result as chart.
+ *
+ * @author Johannes Theiner
+ * @version 0.1
+ * @since 1.0
+ */
+
 let week_result;
 
 let week_overview = new Chart($("#overview_chart"), {
diff --git a/src/main/webapp/theming.jsp b/src/main/webapp/theming.jsp
index d6dcc2f..b0267ea 100644
--- a/src/main/webapp/theming.jsp
+++ b/src/main/webapp/theming.jsp
@@ -5,7 +5,7 @@
 <script type="text/javascript" src="https://code.jquery.com/jquery-2.1.1.min.js"></script>
 
 <script src="js/upload.js"></script>
-<script src="js/cache.js"></script>
+<script src="js/datasets.js"></script>
 <script src="js/week_overview.js"></script>
 <script src="js/shopping_times.js"></script>
 <script src="js/sales.js"></script>