open a custom popup on browser window/tab close

Question

I am trying to open a custom popup on browser window/tab close.

In details if a user clicks on the browser window/tab close button a custom popup will appear with s

Answer 1

i would also suggest you dont do this, but after all, you asked a question and deserve an answer.

this script will work (http://jsfiddle.net/SQAmG/3/) and will make sure that it will only popup once (to not bother the user again if he decided to stay once).