function dispAd(MyFile,MyWindow,MyWidth,MyHeight){
var ns4 = (document.layers)? true:false;    //NS 4
var ie4 = (document.all)? true:false;   //IE 4
var dom = (document.getElementById)? true:false;   //DOM
var xMax, yMax, xOffset, yOffset;
var win=','
+'status=1,'
+'titlebar* = 0,'
+'scrollbars=1,'
+'resizable=1,'
+'status=no, '
+'directories=no,'
+'toolbar=no,'
+'location=no,'
+'menubar=no';

    if (ie4 || dom)
        {
        xMax = screen.width;
        yMax = screen.height;
        }
    else if (ns4)
        {
        xMax = window.outerWidth;
        yMax = window.outerHeight;
        }
    else
        {
        xMax = 800;
        yMax = 600;
        }
    xOffset = (xMax - MyWidth)/2;
    yOffset = (yMax - MyHeight)/2;
    window.open(MyFile,MyWindow,'width='+MyWidth
+',height='+MyHeight
+',screenX='+xOffset
+',screenY='+yOffset
+',top='+yOffset
+',left='+xOffset
+ win);
}
/*

function dispAd(url)
{
var xMax, yMax;

xMax = (screen.width - 800 ) / 2 ;
yMax = (screen.height - 600) / 2 ;
        //var url='test1.htm';
      var win='name1,toolbar=1location=0,status=1,titlebar* = 0,scrollbars=0,resizable=0,width=800,height=600,  status=no, directories=no, toolbar=no, location=no,menubar=no,left='+xMax+',top='+yMax;



               open(url,"",win );


}


*/