[O] how export highlight code

[a machine of awareness]

I'm using org-mode v7.01g.
I've tried to export a code block like this:

#+BEGIN_SRC c -n
      static void doData()
      {
        if (_pStatus->switchChange>0x00)
        {
          _pStatus->switchChange = 0x00;
          _pStatus->workStatus = DATABASE_PRO_WOR_WAIT;
          return;
        }
        ...
      }
#+END_SRC

The result html doesn't highlight the code. Instead it gives me:

<pre class="example"><span class="linenr"> 1:  </span>
<span class="linenr"> 2:  </span>static void doData()
<span class="linenr"> 3:  </span>{
<span class="linenr"> 5:  </span>  if (_pStatus-&gt;switchChange&gt;0x00)
<span class="linenr"> 6:  </span>  {
<span class="linenr"> 7:  </span>    _pStatus-&gt;switchChange = 0x00;
<span class="linenr"> 9:  </span>    _pStatus-&gt;workStatus = 
DATABASE_PRO_WOR_WAIT;
<span class="linenr">10:  </span>    return;
<span class="linenr">11:  </span>  }
<span class="linenr">12:  </span>  ...
<span class="linenr">13:  </span>}
</pre>

And I have not changed any option related to org-babel or the exporting 
function.
So how can I make the syntax highlighting work for exporting to html?
-- 
a machine of awareness
 Debian、Emacs+Gnus