How To Set Image As Background Of Div Tag ..

Question

I have A Image In Session  Variable And I Want To set That Image In Backgroud Of Div Tag How To Do ...

 

This Is My Session :-

 

Session["BackImage"] 

 

 

This Is my Div Tag :- 

 

<div class="container">

<div class="row row-centered pos">

<div class="col-lg-12 col-xs-12 col-centered">

<div class="well bgimg"></div>

</div>

</div>

</div>

 

Please Tell me