352613 exit pop/dialog with redirect

I am looking for a script that is commonly used when someone actually closes the window/tab or hits the back button. A dialog with text will appear with a "OK" button. then a redirect in the current browser window. With a dialog stating. "Press OK to continue, or Cancel to stay on the current page." I have seen this around it may even be a free script somewhere. If user clicks the any link on the page, the exit pop up will not be launched. Only when visitor clicks back or close browser will the pop up /exit pop up launch. It must work on the latest version of IE and FireFox and beat pop up blockers. I would like to see a working example before payment is made. Ask on PMB and I can give and example I am not sure if this is a PHP or J/S thing so I have listed both