How Trigger Window.onblur?

I have a little popup window I'm making. I'd like the window to just destroy itself if the user clicks on the original, calling page.

This is what I tried in the header section of the popup page but the code is not being triggered:

<script type="text/javascript"> <!--
window.
-->
</script>

And by the way I already tried this in the body tag:

And the body tag thing actually DID close the window if the user clicked on the original calling page. BUT the window also closed if the user clicked on a combo box on the popup (because the body lost the focus), and that was not good..