MidX=screen.availWidth/2
MidY=screen.availHeight/2

function popup(URL,WIDTH,HEIGHT)
{
	window.open(URL,'popwin','menubar=no,toolbar=no,location=no,directories=no,status=no,scrollbars=no,resizable=no,copyhistory=no,top='+(MidY-(HEIGHT/2)-30)+',left='+(MidX-(WIDTH/2))+',width='+WIDTH+',height='+HEIGHT+'');
}