Fixed issue #08623: preview image of "multiple numeric" question type…

… is not hidden after choosing

Dev Added event listener for closing the select element
Dev Fixed invalid JS

scripts/admin/admin_core.js

@@ -144,9 +144,9 @@ function qTypeDropdownInit()
     });
     $(document).ready(function() {
         $('body').on('mouseenter mouseleave', 'li.questionType', function(e) {
-            if (e.type = 'mouseenter')
+            if (e.type == 'mouseenter')
             {
-                // Hide all others if we show a new one.
+				// Hide all others if we show a new one.
                 $('#question_type option').qtip('hide');
                 $($(e.currentTarget).data().select2Data.element).qtip('option', 'position.target', $(e.currentTarget)).qtip('show');
             }
@@ -157,6 +157,9 @@ function qTypeDropdownInit()
 
 
         });
+        $('#question_type').on('close', function(e) {
+            $('#question_type option').qtip('hide');
+        });
     });
 }