rounded corner help

I’m trying to breakup this code so that i can add images of rounded corners but i’m not sure whats doing what since its a list class. I’ve found it very difficult to even affect the output because of this, much less break it up into sections for top and bottom corners. This is my left sidebar, you can see it at http://www.sketchygrid.com.
thx.

`<div id=”sidebar_left” class=”sideleft”>

<?php if ( !function_exists(‘dynamic_sidebar’) || !dynamic_sidebar(2) ) : ?>

<li class=”adsensebar”><div>

<h3>Author Info</h3>

<p>You can put anything here, such as author information or any other text. Even easier, add a text widget to Sidebar 2. That way you don’t need to touch this code.</p>

</div>

<li class=”adsensebar”>
<div>
<form method=”get” action=”<?php bloginfo(‘home’); ?>”>
<input type=”text” name=”s” id=”s” size=”12″ />
<input type=”submit” value=”<?php _e(‘Search’); ?>” />
</form></div>

<li class=”adsensebar”>
<div><h3>Categories</h3>

<?php wp_list_categories(‘title_li=’ ); ?>

</div>

<div><h3>Archives</h3>

<?php wp_get_archives(‘type=monthly’); ?>

</div>

<div class=”topcont2″><h3>Meta</h3>

<?php wp_register(); ?>

• <?php wp_loginout(); ?>
• ” title=”<?php _e(‘Syndicate this site using RSS’); ?>”><?php _e(‘<abbr title=”Really Simple Syndication”>RSS</abbr>’); ?>
• ” title=”<?php _e(‘The latest comments to all posts in RSS’); ?>”><?php _e(‘Comments <abbr title=”Really Simple Syndication”>RSS</abbr>’); ?>
• “><?php _e(‘Valid <abbr title=”eXtensible HyperText Markup Language”>XHTML</abbr>’); ?>
• <abbr title=”XHTML Friends Network”>XFN</abbr>
• “><abbr title=”WordPress”>WP</abbr>

<?php wp_meta(); ?>

</div>

<?php endif; ?>

</div>
`