Pop-under when user leaves site

looking for a script...

All the ones I've tried so far haven't distinguished between leaving a page and leaving a site.
Can anyone point me in the direction of a script that will:

- launch a pop-under when a user leaves my site
- does not launch the pop-under when they simply leave a page with the script on to go to another page on my site

and ideally

- doesn't lauch a pop-under when a user clicks a link to an external site that opens in a new window


Help greatly appreciated.

Improper use of windows, such as that, has ruined what should be a helpful tool, for most everyone.
How does a "pop-under" serve to benefit the user, in your scenario?

Entirely agree. The appearance of a pop under window ensures that I leave the site - for good.

Ditto...

I believe I know when I want to leave a site and do not appreciate intrusive efforts to keep me on the site. This would be a sure way to insure that I do not return....

OK thanks, I appreciate your views here, however in this case I am determined to use the pop-under, and would welcome any scripting advice that members here can offer.