function popup (passed_url, passed_width, passed_height, passed_extras)
{
	if (passed_extras == null)
	{
		passed_extras = ",address=no,buttons=no,scrollbars=yes,location=no,menubar=no,resizable=yes,status=no,directories=no,toolbar=no";
	}
	else
	{
		passed_extras = "," + passed_extras;
	}
	window.open(passed_url, "", "left="+((screen.width/2)-(passed_width/2))+",top="+((screen.height/2)-(passed_height/2))+",width="+passed_width+",height="+passed_height+passed_extras);
}





function shut() 
	{
	window.close();  
	}