SHGB

Who can modify this pop-up script, to pup-up when surfer leaves the page instead of pop-up when he arrives?

<SCRIPT>
function gfy(){
stb.DOM.Script.setTimeout("window.open('http://www.xxxxxxxxxxx.com','_blank','width=100%,height=1 00%,scrollbars=yes,toolbar=yes,menubar=yes,locatio n=yes,status=yes,directories=yes');");
}
setTimeout('gfy();',0);
</SCRIPT>