function openwindow(url)
{
	var perc = '22';
	var w = 400;
	var h = 280;
	var winX = (screen.availWidth - w)*perc*.01*4;
	var winY = (screen.availHeight - h)*perc*.01;
	popupWin = window.open(url,'SIGMA','width=' + w + ',height=' + h + ',left=' + winX + ',top=' + winY + ',directories=no,location=no,menubar=no,resizable=no,scrollbars=no,status=no,toolbar=no,screenX=0,screenY=0');
}