function ow(u, n, w, h, s)
{    
    dw = Math.round((screen.availWidth - w) / 2);
    dh = Math.round((screen.availHeight - h) / 2);

	w = window.open (u, n, "width=" + w + ",height=" + h + ",top=" + dh + ",left=" + dw + ",toolbar=0,location=0,directories=0,status=0,menuBar=0,scrollBars=" + s + ",resizable=0");
	w.focus ();
}