rem: var addressbook = Components.classes["@mozilla.org/addressbook;1"].createInstance(Components.interfaces.nsIAddressBook); 
add: var addressbook = Components.classes["@mozilla.org/addressbook;1"] .getService(Components.interfaces.nsIAddressBook);  
context: function mailingListExists(listname){  var addressbook = Components.classes["@mozilla.org/addressbook;1"].createInstance(Components.interfaces.nsIAddressBook);  if (addressbook.mailListNameExists(listname))  {    gPromptService.alert(window,       gAddressBookBundle.getString("mailListNameExistsTitle"),      gAddressBookBundle.getString("mailListNameExistsMessage"));    return true;  }  return false;}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/9421/7bedc789ce4693f8b68d8f9969c41b7272a65e21/abMailListDialog.js/buggy/mailnews/addrbook/resources/content/abMailListDialog.js