function centerPopUp( url, name, width, height, scrollbars )
{

        if( scrollbars == null ) scrollbars = "0"

        str  = "";
        str += "resizable=1,";
        str += "scrollbars=" + scrollbars + ",";
        str += "width=" + width + ",";
        str += "height=" + height + ",";

        if ( window.screen ) {
                var ah = screen.availHeight - 30;
                var aw = screen.availWidth - 10;

                var xc = ( aw - width ) / 2;
                var yc = ( ah - height ) / 2;

                str += ",left=" + xc + ",screenX=" + xc;
                str += ",top=" + yc + ",screenY=" + yc;
        }
        window.open( url, name, str );
}