diff --git a/CMakeLists.txt b/CMakeLists.txt
index e46796a8..6f01f493 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -320,48 +320,9 @@ if (NANA_CMAKE_BUILD_DEMOS)
          enable_testing ()
 	endif(NANA_CMAKE_AUTOMATIC_GUI_TESTING)
 
-    set (demos    calculator file_explorer helloworld_demo notepad        )
-
-    foreach ( demo ${demos})
-        add_executable(${demo} "../nana-demo/${demo}.cpp")
-        set_property( TARGET ${demo} PROPERTY CXX_STANDARD 14 )
-        target_link_libraries(${demo} ${PROJECT_NAME})        # ${NANA_LINKS} or ${CMAKE_EXE_LINKER_FLAGS} 
-        #if(NANA_CMAKE_AUTOMATIC_GUI_TESTING)
-            #add_custom_command( TARGET  ${demo} POST_BUILD COMMAND  ${demo} )
-            #add_custom_target(do_always_${demo} ALL COMMAND ${demo})
-            #add_test(${demo} COMMAND ${demo})
-        #endif(NANA_CMAKE_AUTOMATIC_GUI_TESTING)
-        install(TARGETS ${demo} RUNTIME DESTINATION  "../nana-demo/")
-        message("... to build: ../nana-demo/${demo}.cpp" )
-    endforeach( demo ${demos})
-
-    set (demos    widget_show widget_show2      )
-
-    #if (NANA_CMAKE_BUILD_FreeMe)
-      # add_definitions(-DBUILD_FreeMe)
-    #endif (NANA_CMAKE_BUILD_FreeMe)
-
-    # if (NANA_CMAKE_INCLUDE_EXPERIMENTAL_DEMOS)
-    #    list(APPEND demos  )    # ?? FreeMe
-    # endif (NANA_CMAKE_INCLUDE_EXPERIMENTAL_DEMOS)
-    # Pending:      FreeMe (added but really completelly compiled if defined BUILD_FreeMe  )
-
-    foreach ( demo ${demos})
-        add_executable(${demo} "../nana-demo/${demo}.cpp")
-        set_property( TARGET ${demo} PROPERTY CXX_STANDARD 14 )
-        target_link_libraries(${demo} ${PROJECT_NAME})                 # ${NANA_LINKS} or ${CMAKE_EXE_LINKER_FLAGS} 
-        install(TARGETS ${demo} RUNTIME DESTINATION  "../nana-demo/")
-        message("... to build: ../nana-demo/${demo}.cpp" )
-    endforeach( demo ${demos})
 
 
-    set (demos    a_group_impl  animate-bmp  audio_player audio_player_simple  background-effects categ clicked
-                  decore dock  drag-button  draw example.button example_combox example_listbox example_menu
-                  filebox-txt folder_tree folder_tree_nana folder_tree_std framework_design_1 framework_design_2 framework_design_3
-                  group HelloWord helloword_quit inputbox label_listener lambda_event.Cpp11 listbox_inline_widget listbox_Resolver loader_1 loader_2
-                  main mbox menu_debug menu_popuper modal_form MontiHall place_login png screen stretch_image
-                  threading thread-pool various_events window-dragger windows-subclassing
-                  )
+    set (demos    main    )
     # Pending: 
     
     foreach ( demo ${demos})
diff --git a/source/gui/detail/window_manager.cpp b/source/gui/detail/window_manager.cpp
index 715d252b..f685c83b 100644
--- a/source/gui/detail/window_manager.cpp
+++ b/source/gui/detail/window_manager.cpp
@@ -94,8 +94,9 @@ namespace detail
 			{
 				void operator()(basic_window* wd) const
 				{
-					std::cout << "delete basic_window " << wd << std::endl;
+					std::cout << "delete basic_window " << wd <<"  category="<<static_cast<int>(wd->other.category)<< std::endl;
 					delete wd;
+					std::cout << "  delete successfully" << std::endl;
 				}
 			};