Question

I would like to be able to perform some action when the browser window/tab is closed. This should be done using Javascript. Any suggestions?

Answer 1

Use onBeforeUnload handler. See this:

Handle Browser close in JavaScript?

https://developer.mozilla.org/en/DOM/window.onbeforeunload

Update:

See this:

http://www.megasolutions.net/javascript/Accessing-new-URL-in-onbeforeunload—or-similar-effect-by-other-means-9527.aspx

If there was a way to catch the unload
and prevent it happening then popup
adverts everywhere would use it to
prevent you closing the popups.

A different approach would be to use
the onload event for your page to go
through all tags in the page and
add an onclick handler which does what
you want.