function getID($ConditionString,$Rest=null)
    {
        $args=func_get_args();
        array_shift($args);
        $Query="SELECT {$this->id()} AS ID FROM {$this->table()} WHERE $ConditionString LIMIT 1";
        array_unshift($args,$Query);
        $Res=call_user_func_array(("Jf::sql"),$args);
        if ($Res)
        return $Res[0]["ID"];
        else
        	return null;
    }