fixed minor code style issues

app/assets/javascripts/dashboard.js

@@ -2,9 +2,9 @@ $(function() {
   var CHART_START = window.vis ? vis.moment().add(-1, 'minute') : undefined;
   var DEFAULT_REFRESH_INTERVAL = 5000;
 
-  var dataset = undefined;
+  var dataset;
-  var graph = undefined;
+  var graph;
-  var groups = undefined;
+  var groups;
 
   var buildChartGroups = function() {
     return _.map($('tbody tr[data-id]'), function(element) {

app/assets/javascripts/editor.js

@@ -13,8 +13,8 @@ $(function() {
   var THEME = 'ace/theme/textmate';
 
   var editors = [];
-  var active_file = undefined;
+  var active_file;
-  var active_frame = undefined;
+  var active_frame;
   var running = false;
 
   var flowrUrl = 'http://vm-teusner-webrtc.eaalab.hpi.uni-potsdam.de:3000/api/exceptioninfo?id=&lang=auto';
@@ -107,7 +107,7 @@ $(function() {
   };
 
   var evaluateCode = function(url, streamed, callback) {
-    eval('evaluateCode' + (streamed ? 'With' : 'Without') + 'StreamedResponse')(url, callback);
+    (streamed ? evaluateCodeWithStreamedResponse : evaluateCodeWithoutStreamedResponse)(url, callback);
   };
 
   var evaluateCodeWithStreamedResponse = function(url, callback) {

app/assets/javascripts/exercises.js

@@ -65,7 +65,7 @@ $(function() {
     $('code').on('click', function() {
       $(this).css({
         'max-height': 'initial'
-      })
+      });
     });
   };