load external web page into a div using jQuery

To load external web page into a div using jQuery, first we create a link with class menu_top:
<a class="menu_top" href="home.php>Home </p>
We want  to load home.php  into the div with id content_area: when the link is clicked:
<div id="content_area"></div>
jQuery function load is used:
$('.menu_top').click(function(){
       var href= $(this).attr('href');
       $('#content_area').load(href);
       return false;
});
If we want to load home.php  into the div automatically without click the link:
$(document).ready(function(){
       var href= $('.menu_top:first').attr('href');
       $('#content_area').load(href);
}).
assume we have several div with class menu_top, we want to load the first one.