function popup(url) {
	var x = screen.availWidth / 2 - 640 / 2;
	var y = 20;
	if (navigator.userAgent.indexOf("MSIE") != -1) {
		y = screen.availHeight / 2 - 480 / 2;
	}
	window.open("maxi.php?url="+url, "Popup", "width=1,height=1,left="+x+",top="+y);
	return false;
}