Wordpress modify the_content markup

With jQuery or PHP, I would like to modify the dom structure of the the_content function in WordPress. In some posts I use the h3 element, and I would like to add a wrapper that contains the cont开发者_运维知识库ent until the next h3.

So I would like to convert this:

<h3>Title</h3>
<p>This is just regular text</p>
<h3>Next title</h3>

Into this:

<div class='wrapper'>
  <h3>Title</h3>
  <p>This is just regular text</p>
</div>
<div class='wrapper'>
  <h3>Next title</h3>
</div>

Thanks!

assuming that the content only consists of <h3>s and <p>s,and they are welled formated like:

<div id="content">
   <h3>title</h3>
    <p>..........</p>
    <p>..........</p>
   <h3>another title</h3>
    <p>.........</p>
   <h3>yet another title</h3>
    <p>..........</p>
 </div>

then you may try this in jQuery.

  //get the main post content
  $content=$("#content");
  $h3s=$content.find('h3');
  $h3s.each(function(index){
       if(index==0)$(this).before('<div class="wrapper">');           
       else $(this).before('</div><div class="wrapper">');
  });
  //remeber to close the last one
  $content.append('</div>');