function popup (url, popup_width, popup_height) {
	var left = (screen.width / 2) - (popup_width / 2);
	var top = (screen.height / 2) - (popup_height / 2);	
	//popup_height = popup_height + 25;
	aWindow=window.open(url,"","toolbar=no,width="+popup_width+",height="+popup_height+",status=no,scrollbars=no,resize=no,menubars=no,left="+left+",top="+top);
	//aWindow.document.writeln ('<p align="center"><a href="javascript:window.close()">[Close window]</a></p>');
}