How to add a div to a home page

Hi all,

I’m using the Denali theme (preview: https://173.254.28.82/~thevine4/) and I’m trying to get another full length div between the slideshow and the content area under it.

I believe the slideshow area is called
<div class=”sld-flexible-wrapper overlay_search_form”>
and the other area is called
<div id=”content” class=”inner_content_wrapper have-sidebar”>

I’m using Firebug but I was not able to work out in what file the div’s are to add another div.

I’m not sure if I should add a div between existing divs or add one div in eiter of the existing divs and tell it to be full width?

Suggestions and help are very welcome ??

Thanks!