diff --git a/js/module/graph.js b/js/module/graph.js
index 3e8bfef000cb109baa243ab68f34f0493a969710..726875695e2d112f255fb81aa92f6d9274dcef9c 100644
--- a/js/module/graph.js
+++ b/js/module/graph.js
@@ -1,11 +1,13 @@
-var s = null, graph = null, graphMode = null, sigmaCanvas = null;
+var s = null, graph = null, sigmaCanvas = null;
 
 function GraphTracer(module) {
-    Tracer.call(this, module || GraphTracer);
-    return initGraph(this.module);
+    if (Tracer.call(this, module || WeightedGraphTracer)) {
+        initGraph();
+        return true;
+    }
+    return false;
 }
 
-GraphTracer.graphMode = "default";
 GraphTracer.prototype = Object.create(Tracer.prototype);
 GraphTracer.prototype.constructor = GraphTracer;
 
@@ -59,7 +61,6 @@ GraphTracer.prototype.setTreeData = function (G, root) {
     if (this.setData(G, root)) return true;
 
     var place = function (node, x, y) {
-        console.log(node);
         var temp = graph.nodes(n(node));
         temp.x = x;
         temp.y = y;
@@ -190,10 +191,7 @@ GraphTracer.prototype.prevStep = function () {
     this.step(finalIndex);
 };
 
-var initGraph = function (module) {
-    if (s && graph && graphMode == module.graphMode) return false;
-    graphMode = module.graphMode;
-
+var initGraph = function () {
     $('.visualize_container').empty();
     if (sigmaCanvas == null) {
         sigmaCanvas = $.extend(true, {}, sigma.canvas);
@@ -232,8 +230,6 @@ var initGraph = function (module) {
         drawArrow(edge, source, target, color, context, settings);
     };
     sigma.plugins.dragNodes(s, s.renderers[0]);
-
-    return true;
 };
 
 var graphColor = {
diff --git a/js/module/weighted_graph.js b/js/module/weighted_graph.js
index 85edbddae470850583ccd4481fa6572e2883cd0c..73df8d9613a2997ea0fc5041dc2961c00f2f5ff3 100644
--- a/js/module/weighted_graph.js
+++ b/js/module/weighted_graph.js
@@ -6,7 +6,6 @@ function WeightedGraphTracer(module) {
     return false;
 }
 
-WeightedGraphTracer.graphMode = "weighted";
 WeightedGraphTracer.prototype = Object.create(GraphTracer.prototype);
 WeightedGraphTracer.prototype.constructor = WeightedGraphTracer;
 
diff --git a/js/script.js b/js/script.js
index f35389f6915588483dcdb3c780ab133199b9aed7..85850f30a3d6de1e4ac5471350e19f907e480326 100644
--- a/js/script.js
+++ b/js/script.js
@@ -13,6 +13,7 @@ var codeEditor = initEditor('code');
 dataEditor.on('change', function () {
     try {
         eval(dataEditor.getValue());
+        lastModule = _tracer && _tracer.module;
         _tracer = tracer;
     } catch (err) {
     }
@@ -20,7 +21,6 @@ dataEditor.on('change', function () {
 });
 
 var loadFile = function (category, algorithm, file, explanation) {
-    lastModule = null;
     lastData = null;
     $('#explanation').html(explanation);
     dataEditor.setValue('');
@@ -134,6 +134,7 @@ $('#navigation').click(function () {
 $('#btn_run').click(function () {
     try {
         eval(dataEditor.getValue());
+        lastModule = _tracer && _tracer.module;
         _tracer = tracer;
         _tracer.reset();
         eval(codeEditor.getValue());
diff --git a/js/tracer.js b/js/tracer.js
index 115333b30409a3384ea1273c6be0d1d7d086d780..3cd046d7eed3e60bd3b01356faaa4373a4ef5e0b 100644
--- a/js/tracer.js
+++ b/js/tracer.js
@@ -9,6 +9,8 @@ var Tracer = function (module) {
     this.traceOptions = null;
     this.traceIndex = -1;
     this.stepCnt = 0;
+
+    return lastModule != module;
 };
 
 Tracer.prototype.resize = function () {
@@ -30,8 +32,7 @@ Tracer.prototype.createRandomData = function (arguments) {
 
 Tracer.prototype.setData = function (arguments) {
     var data = JSON.stringify(arguments);
-    if (lastModule == this.module && lastData == data) return true;
-    lastModule = this.module;
+    if (lastData == data) return true;
     lastData = data;
     return false;
 };