Added a new file for the key symbols, using the well recognized names for the constants from X11:

* The list is found in /usr/include/X11/keysymdef.h
* I did only include the most common symbols for now..

LICENSE.txt

@@ -10,6 +10,7 @@ is not limited to):
     include/display.js
     include/input.js
     include/jsunzip.js
+    include/keysym.js
     include/logo.js
     include/rfb.js
     include/ui.js

include/ui.js

@@ -14,7 +14,8 @@
 // Load supporting scripts
 window.onscriptsload = function () { UI.load(); };
 Util.load_scripts(["webutil.js", "base64.js", "websock.js", "des.js",
-                   "input.js", "display.js", "jsunzip.js", "rfb.js"]);
+                   "input.js", "display.js", "jsunzip.js", "rfb.js",
+                   "keysym.js"]);
 
 var UI = {
 
@@ -764,43 +765,39 @@ showExtraKeys: function() {
 },
 
 toggleCtrl: function() {
-    var ctrlKeysum = 0xFFE3;
     UI.keepKeyboard();
     if(UI.ctrlOn === false) {
-        UI.rfb.sendKey(ctrlKeysum, true);
+        UI.rfb.sendKey(XK_Control_L, true);
         $D('toggleCtrlButton').className = "noVNC_status_button_selected";
         UI.ctrlOn = true;
     } else if(UI.ctrlOn === true) {
-        UI.rfb.sendKey(ctrlKeysum, false);
+        UI.rfb.sendKey(XK_Control_L, false);
         $D('toggleCtrlButton').className = "noVNC_status_button";
         UI.ctrlOn = false;
     }
 },
 
 toggleAlt: function() {
-    var altKeysum = 0xFFE9;
     UI.keepKeyboard();
     if(UI.altOn === false) {
-        UI.rfb.sendKey(altKeysum, true);
+        UI.rfb.sendKey(XK_Alt_L, true);
         $D('toggleAltButton').className = "noVNC_status_button_selected";
         UI.altOn = true;
     } else if(UI.altOn === true) {
-        UI.rfb.sendKey(altKeysum, false);
+        UI.rfb.sendKey(XK_Alt_L, false);
         $D('toggleAltButton').className = "noVNC_status_button";
         UI.altOn = false;
     }
 },
 
 sendTab: function() {
-    var tabKeysum = 0xFF09;
     UI.keepKeyboard();
-    UI.rfb.sendKey(tabKeysum);
+    UI.rfb.sendKey(XK_Tab);
 },
 
 sendEsc: function() {
-    var escKeysum = 0xFF1B;
     UI.keepKeyboard();
-    UI.rfb.sendKey(escKeysum);
+    UI.rfb.sendKey(XK_Escape);
 },
 
 setKeyboard: function() {