[S2] Complex submit button issue

I'm using the css_xhtml theme and trying to create a submit button that outputs something like:

<button type="button" class="button positive save">
     Save
</button>

I would expect something like this to work:
<s:submit type="button"
  cssClass="button positive save"
  value="">
    Save    
</s:submit>

But it outputs (formatted):
<img src="/core/images/tick.png" alt="Save"/> Save    
<div align="right"    id="wwctrl_search_0">
    <button type="submit" id="search_0" value="" class="button positive save"></button>
</div>

I thought that maybe whatever was inside the s:submit tag would be used as the value, but no such luck. Is that value held somewhere? If it is, I could just edit the template to display it...

Is there a struts way to do this, or should I just use standard HTML?

Thanks,
Eric