var newWin = null;

function closeWin()
{
	if (newWin != null)
	{
		if(!newWin.closed)
			newWin.close();
	}
}

function windowPopup(urlName, imgWidth, imgHeight)
{
     closeWin();
	 var width = imgWidth;
     var height = imgHeight;

     var str = 'height=' + height + ',innerHeight=' + height;
     str += ',width=' + width + ',innerWidth=' + width;

     if (window.screen)
     {
         var ah = screen.availHeight - 100;
         var aw = screen.availWidth - 10;
         var xc = (aw - width) / 2;
         var yc = (ah - height) / 2;
         str += ',left=' + xc + ',screenX=' + xc;
         str += ',top=' + yc + ',screenY=' + yc;
     }
     newWin = window.open(urlName,'newWin','titlebar=no,directories=no,toolbar=no,resizable=no,scrollbars=no,status=no,menubar=no,' + str);	 
	 newWin.focus();
}