function openWindow(url,windowName,width,height){

    var x = parseInt(screen.width / 2.0) - (width / 2.0);

    var y = parseInt(screen.height / 2.0) - (height / 2.0);

    var isMSIE= (navigator.appName == "Microsoft Internet Explorer");

    if (isMSIE) {

        var p = "resizable=1,location=no,scrollbars=no,width=";

        p = p+width;

           p = p+",height=";

           p = p+height;

        p = p+",left=";

        p = p+x;

        p = p+",top=";

        p = p+y;

        retval = window.open(url, windowName, p);

    } else {

        var win = window.open(url, "ZyiisPopup", "top=" + y + ",left=" + x + ",scrollbars=" + scrollbars + ",dialog=yes,modal=yes,width=" + width + ",height=" + height + ",resizable=no" );

        eval("try { win.resizeTo(width, height); } catch(e) { }");

        win.focus();

    }