Image banner not appearing in forum

Hi

I am trying to insert a simple basic image banner into my forum for testing purposes but it appears that it is not working for me or maybe that i am doing something totally wrong here.

Just need so helpful tips.

Thanks.<div class="windowbg">

<span class="topslice"><span></span></span>

<div class="content">

{content}

</div>

<span class="botslice"><span></span></span>

</div>