var wh = null;

function winOpen(url, width, height)
{
	if(wh != null) wh.close();
	properties = 'top=' + (screen.height/2 - height/2) + ',left=' + (screen.width/2 - width/2) + 'toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=yes,titlebar=no,width=' + width + ',height=' + height;
	wh = window.open(url,'_blank',properties);
	wh.focus();
}