function popup(popupURL, w, h, scr) {
    var wx = w + 16;
	var hx = h + 16;
	var xPos = (screen.availWidth / 2) - (wx/2);
	var yPos = (screen.availHeight / 2) - (hx/2) - 20;
	window.open(popupURL, "popupURL", "toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=" + scr + ",copyhistory=0,resizable=1,width=" + wx + ",height=" + hx + ",left=" + xPos + ",top=" + yPos);
}