diff --git a/CMakeLists.txt b/CMakeLists.txt
index ac80de4..463cbc4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,38 +1,13 @@
 cmake_minimum_required(VERSION 3.7.2)
 
-if ("${CMAKE_BINARY_DIR}" STREQUAL "${CMAKE_SOURCE_DIR}")
-    message(FATAL_ERROR "In-source builds are disabled.
-    Please create a subfolder called build and use `cmake ..` inside it.
-    NOTE: cmake will now create CMakeCache.txt and CMakeFiles/*.
-          You must delete them, or cmake will refuse to work.")
-endif()
-set_property(DIRECTORY APPEND PROPERTY ADDITIONAL_MAKE_CLEAN_FILES "bin" "doc" "CMakeFiles" "lib" "include")
-
 project(GUI)
 set(CMAKE_CXX_STANDARD 14)
 
-# enable clang_tidy
-set(CMAKE_CXX_CLANG_TIDY "clang-tidy;-checks=*")
-set(CMAKE_CXX_CLANG_TIDY clang-tidy;-header-filter=.;-checks=*;)
-
-file(GLOB_RECURSE SOURCES src/*.cpp)
-file(GLOB_RECURSE HEADERS src/*.h)
-file(GLOB_RECURSE TESTS test/*.cpp)
-
-set(LIB_PATH "${CMAKE_SOURCE_DIR}/../library")
-
-include_directories(${LIB_PATH}/include)
 add_executable(GUI ${SOURCES} ${HEADERS} main/main.cpp)
 
-target_link_libraries(GUI ${LIB_PATH}/lib/liblibrary.a)
+set(FLTK_SKIP_FLUID true)
+find_package(FLTK REQUIRED)
+include_directories(${FLTK_INCLUDE_DIR})
+target_link_libraries(${PROJECT_NAME} ${FLTK_BASE_LIBRARY} ${FLTK_PLATFORM_DEPENDENT_LIBS})
 
-#TODO: add fltk here
 
-enable_testing()
-find_package(Catch2 REQUIRED)
-add_executable(UnitTests ${SOURCES} ${HEADERS} ${TESTS})
-target_link_libraries(UnitTests Catch2::Catch2)
-
-include(CTest)
-include(Catch)
-catch_discover_tests(UnitTests)
diff --git a/main/main.cpp b/main/main.cpp
index 53edc26..f6f9ab1 100644
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -1,5 +1,28 @@
-#include "../src/demo.h"
+#include <FL/Fl.H>
+#include <FL/Fl_Window.H>
+#include <FL/Fl_Button.H>
+#include <iostream>
 
-int main() {
-    return test();
+
+using namespace std;
+
+void button_cb(Fl_Widget* wid){
+    Fl_Button* but = (Fl_Button*)wid;
+
+    if(but->label()=="&Good job"){
+        but->label("&Click me");
+    } else
+        but->label("&Good job");
+    but->redraw();
+}
+
+int main(int argc, char **argv) {
+  Fl_Window win(300,200,"Testing");
+  int i = 7;
+  win.begin();
+  Fl_Button but(20,150,70,30,"&Click me");
+  win.end();
+  but.callback(button_cb);
+  win.show();
+  return Fl::run();
 }
\ No newline at end of file