rem: prefs = Components.classes['@mozilla.org/preferences;1']; if (prefs) prefs = prefs.getService(); if (prefs) prefs = prefs.QueryInterface(Components.interfaces.nsIPref); 
add: var prefService = Components.classes["@mozilla.org/preferences-service;1"] .getService(Components.interfaces.nsIPrefService); var prefs = prefService.getBranch(null); 
context: function GetPrefs(){  var prefs;  try {    prefs = Components.classes['@mozilla.org/preferences;1'];    if (prefs) prefs = prefs.getService();    if (prefs) prefs = prefs.QueryInterface(Components.interfaces.nsIPref);    if (prefs)      return prefs;    else      dump("failed to get prefs service!\n");  }  catch(ex)  {    dump("failed to get prefs service!\n");  }  return null;}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/faf03ce445712b372523f881cc3144cfadc7a611/EdDialogCommon.js/buggy/editor/ui/dialogs/content/EdDialogCommon.js