How to add logged in user avatar in fixed navbar?

[giri]

I'm using Bootstrap v2.2.1. My site is responsive now. My navbar height is 
60px. I would to add mini user avatar in front of username. 

This is how my code looks like..

<ul class="nav pull-right">
> <li><a href="#">Username</a></li>
> <li class="divider-vertical"></li>
> <li><a href="#"> Logout</a></li>
> </ul>  


Can anyone help me? Thanks