add:  return false; 
context: function gotoHistoryIndex( aEvent )  {	  var index = aEvent.target.getAttribute("index");	  if (index)       {        appCore.gotoHistoryIndex(index);	      return true;	    }	  else       {	      var id = aEvent.target.getAttribute("id");	      if (id == "menuitem-back")	        BrowserBack();	      else if (id == "menuitem-forward")	        BrowserForward();      }  }
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/cf94d24c9b27549885adf402667aac29347917dc/navigator.js/clean/suite/browser/navigator.js