function popup(url) {

	var h = 400;
	var w = 425;

	var t = (screen.height/2)-(h/2);
	var l = (screen.width/2)-(w/2);

	window.open (url, "popupWindow","status=0,toolbar=0,location=0,menubar=0,resizable=1,scrollbars="+scroll+",height="+h+",width="+w+",top="+t+",left="+l);

}