change menu item when user is login

change menu item when user is login

Good morning to everybody,

I have this  menu:
<li><a>Area login</a>
<ul>
        <li><a href="#">Registrati</a></li>
        <li><a href="#">Login</a></li>  
</ul>

I would like that it changes when user has been login:

<ul>
        <li><a href="#">Chat</a></li>
        <li><a href="#">Logout</a></li>

I control if user is login with php instruction:

 if(isset($_SESSION['mail'])) ........

Please can some one help me to realize that?

Thanks in advance

Tegatti