code: function (evt) {
          var propagate = true;
  
          // Collect right mouse clicks from the mouseup
          //  IE - ignores the second right click in mousedown so using
          //  mouseup instead
          if (this.checkModifiers(evt) && this.control.handleRightClicks &&
             OpenLayers.Event.isRightClick(evt)) {
              propagate = this.rightclick(evt);
          }
  
          return propagate;
      }
docs: Method: mouseup
  Handle mouseup.  Installed to support collection of right mouse events.
  
  Returns:
  {Boolean} Continue propagating this event.