function popup(url)
{
	var winx = (screen.availWidth - 475) / 2;
	var winy = (screen.availHeight - 680) /2;
	newwindow=window.open(url,'popup','height=680,width=475,left='+winx+',top='+winy+',resizable=yes,');
	if (window.focus) {newwindow.focus()}
	return false;
}