function credits()
{
//	var width=500;
//	var height=170;
//	var left=(screen.width-width)/2;
//	var top=(screen.height-height)/2;
//	str = 'top=' + top + ', left=' + left + ', width=' + width + ' ,height=' + height +', scrollbars=no';
	var str = 	'top=20, left=20, width=500 ,height=170, scrollbars=no';
	window.open('/credits.html','credits', str);
}