Begin adding control area. Remove un-needed comment.

js/GUI.Utils.js

@@ -0,0 +1,8 @@
+function openTab(tabName) {
+    var i;
+    var x = document.getElementsByClassName("tab");
+    for (i = 0; i < x.length; i++) {
+        x[i].style.display = "none"; 
+    }
+    document.getElementById(tabName).style.display = "block"; 
+}