function click (e) {

   if (!e) e = window.event;

   if ((e.type && e.type == "contextmenu") || (e.button && e.button == 
2) || (e.which && e.which == 3)) {

     alert("Die rechte Maustaste ist gesperrt!");

     return false;

   }

  }

  if (document.layers) document.captureEvents(Event.MOUSEDOWN);

  document.onmousedown = click;

  document.oncontextmenu = click;