How do I remove the pop up message when disabling right click?

Question

I used this piece of code form a website that disables JS. When I right click, the pop up box appears. I'm not JS savvy and I don't know how to disable it. I just want the action itself, not the message. Any help would me appreciated!

 <script language=JavaScript>
     var message="Function Disabled!";

  if (document.layers){
   document.captureEvents(Event.MOUSEDOWN);
   document.onmousedown=clickNS4;
  }
   else if (document.all&&!document.getElementById){
   document.onmousedown=clickIE4;
  }

  document.oncontextmenu=new Function("alert(message);return false")
</script>