function open_popup(url) {
	var width = 852;
	var height = 527;
	var screenX = screen.width
	var screenY = screen.height

	var x = (screenX - width)/2;
	var y = (screenY - height)/2;

var popup = window.open(url,"temp_unavailable","width=" + width + ",height=" + height + ", top=" + y + ", left=" + x)
popup.focus();
}