protected function load_messages(){
        if($this->messages == NULL || $this->locale != $this->messagesLocale){
            if($this->locale != NULL){
                if(file_exists($this->dir_content . "_$this->locale" . '.txt')){
                    $this->messages= file($this->dir_content . "_$this->locale" . '.txt');
                    $this->messages= $this->parse_properties($this->messages);
                    $this->messagesLocale= $this->locale;
                }
            }
            if($this->messages == NULL){
                $this->messages= file($this->dir_content . '.txt');
                $this->messages= $this->parse_properties($this->messages);
                $this->messagesLocale= NULL;
            }
        }
    }