rem: window.openDialog(getBrowserURL(), "_blank", "chrome,all,dialog=no", xlateURL('urn:clienturl:composer:spellcheckers')); 
add: window.open(parent.hPrefWindow.getPref("localizedstring", "editor.spellcheckers.url")); 
context: function SelectLanguage(aTarget) {  try {    if (aTarget.value != "more-cmd")      gLastSelectedLang = aTarget;    else {      window.openDialog(getBrowserURL(), "_blank", "chrome,all,dialog=no",                        xlateURL('urn:clienturl:composer:spellcheckers'));      if (gLastSelectedLang)        document.getElementById("languageMenuList").selectedItem = gLastSelectedLang;    }  } catch (ex) {    dump(ex);  }}
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/f6e8ef1d9037bd67ef346be23079c15e8b818959/pref-composing_messages.js/buggy/mailnews/compose/prefs/resources/content/pref-composing_messages.js