61335 Javascript Slide in Popup

I would like a script that will put up a slide in popup like slideinadgenerator.com. Here are the twists that I'd like to add. >I want the slide in to come up when you close the window, but only if you don't click on a specific link >If possible, I'd like the contents of the popup to come from an html file that is separate. The idea behind the loading is this. You have a second order page, and if the customer clicks on the link for that, then the popup doesn't come up, but if they click back, or close, than it comes up and gives a new sales pitch or tries to get them to take some action. At the end of the project I want to own 100% rights to the script, just as if I'd programmed it myself.