function openWindow(url,widthpx,heightpx) {
	var toppx = (screen.availHeight/2)-(heightpx/2)
	var leftpx = (screen.availWidth/2)-(widthpx/2)
	window.open(url,'PopUp','width='+widthpx+',height='+heightpx+',left='+leftpx+',top='+toppx+',scrollbars=yes,resizable=yes')
}