How could I take only the contents of a specific DIV while using AJAX?

How could I take only the contents of a specific DIV while using AJAX?

Hi everyone! , It's my first post here in jQuery forums. I have something to ask about using AJAX to fetch specific DIV tag contents from the target page. 

Let say I call it on the referring page:

$.ajax({
      type: "POST",
      url: "the_target_page.php",
      success: function(data) {
            // Some data here      
      }
});

and the target page:

<html>
      <head>
      </head>
            <body>
                  <div id="formWrapper">

                        <div id="maincontents">
                               // Here is the data I want to fetch
                               <h1>blah blah blah</h1>
                        </div>

                  </div>
            </body>
</html>

How will I gather just the data on that specific tag?  I just wanted to separate display from AJAX and direct call.

Thanks.