title: Theme a custom menu with theme_menu_tree()
body: <p>I'm trying to override a custom menu output in a block so that instead of </p>
  
  <pre><code>    &lt;ul class="menu"&gt;...&lt;/ul&gt;
  </code></pre>
  
  <p>I can get </p>
  
  <pre><code>    &lt;select name="menu title"&gt;...&lt;/select&gt;
  </code></pre>
  
  <p>In Drupal 6, I could use function <code>theme_menu_tree($tree,$menu_name="") {...}</code> but this doesn't work in Drupal 7 with function <code>theme_menu_tree($variables) {...}</code>.</p>
  
  <p>I've tried <code>theme_menu_tree__mymenu($variables) {...}</code> with no success.  How do I specify a unique menu in Drupal 7?</p>
  
  <p>Thanks.</p>