function OpenWindowCenter(url, theWidth, theHeight)
{
    var theTop   = (screen.height/2)-(theHeight/2);
    var theLeft  = (screen.width/2)-(theWidth/2);

    var features =  'height='+theHeight+',width='+theWidth+',top='+theTop+',left='+theLeft+",scrollbars=yes";

    theWin=window.open(url,'',features);
}