function popup(popupURL, w, h, scr) {
	var xPos = (screen.availWidth / 2) - (w/2);
	var yPos = (screen.availHeight / 2) - (h/2) - 20;
	window.open(popupURL, "popupURL", "toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=" + scr + ",copyhistory=0,resizable=1,width=" + w + ",height=" + h + ",left=" + xPos + ",top=" + yPos);
}