function openWindow(url,winName,width,height)
{
 var left = (screen.width/2) - (width/2);
 var top = (screen.height/2) - (height/2);
 var popWin = window.open(url, 'window', 'left=' + left + ', top=' + top + ', width=' + width + ', height=' + height + ', scrollbars, resizable');
}