rem: if (index != "nothing_available" && value) 
add: if (index != "nothing_available" && value) 
context: function executeUrlBarHistoryCommand( aTarget)   {    var index = aTarget.getAttribute("index");    var value = aTarget.getAttribute("value");    if (index != "nothing_available" && value)       {        gURLBar.value = value;        BrowserLoadURL();      }  } 
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/0a116c7a4692ec031ac7194f38e926f30de12f05/sessionHistoryUI.js/clean/xpfe/browser/resources/content/sessionHistoryUI.js