function zoom(url, width, height) {
      
        var windowX = Math.ceil( (window.screen.width-width) / 2 );
        var windowY = Math.ceil( (window.screen.height-height) / 2 );
        var Win = window.open(url,"displayWindow",'width=' + width + ',height=' + height + ',resizable=0,scrollbars=no,menubar=no' );
        Win.moveTo  ( Math.ceil( windowX ) , Math.ceil( windowY ) );
}