Yesterday I found a bug in FCK editor every time when I was clicking on source code it was adding this weird script
<input type="hidden" id="gwProxy"><!--Session data--></input><input type="hidden" id="jsProxy" onclick="jsCall();" />
in text panel.
I just struggled a lot to find solution and just though to share with all of you guys.
Problem caused by firefox add-on “browser highlighter”. So just remove “browser highlighter” add-on from your firefox and its done!
I hope you know how to remove add-on from firefox!