rem: folder.reveal(); 
add: try { folder.reveal(); } catch (ex) {    var uri = Components.classes["@mozilla.org/network/standard-url;1"] .createInstance(Components.interfaces.nsIURI); uri.spec = "file:  var protocolSvc = Components.classes ["@mozilla.org/uriloader/external-protocol-service;1"] .getService(Components.interfaces.nsIExternalProtocolService); protocolSvc.loadUrl(uri); } 
context: function showFolder(){  var folderList = document.getElementById("downloadFolderList");  var folder = null;    switch (folderList.selectedIndex) {  case 0:    folder = getDownloadsFolder("Desktop");    break;  case 1:    folder = getDownloadsFolder("Downloads");    break;  case 2:    var path = document.getElementById("downloadFolder").getAttribute("path");    folder = Components.classes["@mozilla.org/file/local;1"].createInstance(Components.interfaces.nsILocalFile);    folder.initWithPath(path);    break;  }  folder.reveal();}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/ff9db7b110791e119fd540ddc5fa2288a2d37ac7/pref-downloads.js/buggy/toolkit/mozapps/downloads/content/pref-downloads.js