Edit Any Kind of Website with this javascript

Copy the script below and paste it in any website... !! U can edit all the
contents but u cant save it !! :-(

javascript:document.body.contentEditable='true'; document.designMode='on'; void 0

for ex:

goto http://www.google.co.in/ig?hl=en

Paste the above script in the address bar and see the change :)