gDirty = PR_TRUE;
PREF_ClearUserPref(const char *pref_name){    PrefResult success = PREF_ERROR;    PrefHashEntry*       pref;    if (!gHashTable.ops)        return PREF_NOT_INITIALIZED;    pref = pref_HashTableLookup(pref_name);    if (pref && PREF_HAS_USER_VALUE(pref))    {        pref->flags &= ~PREF_USERSET;        if (gCallbacksEnabled)            pref_DoCallback(pref_name);        success = PREF_OK;    }    return success;}