diff --git a/src/main/webapp/js/upload.js b/src/main/webapp/js/upload.js
index 5c187d0..635c698 100644
--- a/src/main/webapp/js/upload.js
+++ b/src/main/webapp/js/upload.js
@@ -17,27 +17,23 @@ form.onsubmit = function (event) {
 
     let xhr = new XMLHttpRequest();
 
-    xhr.onloadstart = function(e) {
+    xhr.onloadstart = function (e) {
         loading.removeClass("hide");
         $('.sidenav').sidenav('close');
         loading.modal('open');
     };
 
-    xhr.onreadystatechange = function() {
-        if (xhr.readyState == XMLHttpRequest.DONE) {
-            if(xhr.responseText != null) {
-                loading.modal('close');
-                console.log(xhr.responseText);
-                $('#error-message').text(xhr.responseText);
-                error.modal('open');
-            }
-        }
-    }
-
     xhr.onloadend = function (e) {
         clearSelected();
+        if (/[a-z]/.test(xhr.responseText)) {
+            console.log(xhr.responseText);
+            loading.modal('close');
+            $('#error-message').text(xhr.responseText);
+            error.modal('open');
+        }
         updateDatasets();
         form.reset();
+
     };
 
     xhr.open('POST', form.getAttribute('action'), true);
diff --git a/src/main/webapp/menu.jsp b/src/main/webapp/menu.jsp
index 9b7d49f..b4b56f1 100644
--- a/src/main/webapp/menu.jsp
+++ b/src/main/webapp/menu.jsp
@@ -144,15 +144,16 @@
     <div class="modal-footer">
 
     </div>
+</div>
 
-    <div id="error" class="modal">
-        <div class="modal-content">
-            <h4>Es ist ein Fehler aufgetreten</h4>
-            <p id="error-message">A bunch of text</p>
-        </div>
-        <div class="modal-footer">
-            <a href="#!" class="modal-close waves-effect waves-green btn-flat">Ok</a>
-        </div>
+<div id="error" class="modal">
+    <div class="modal-content">
+        <i class="material-icons">error_outline</i>
+        <h2 class="center">Fehler</h2>
+        <h4 id="error-message" class="center">Hallo Welt, das sollte nie zu sehen sein.</h4>
+    </div>
+    <div class="modal-footer">
+        <a href="#!" class="modal-close waves-effect waves-green btn-flat">Ok</a>
     </div>
 </div>