【appendto】
<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js'></script>
<script type='text/javascript'>
$(function(){
$('#main_menu li').click(function() {
$(this).appendTo('.main_content ul')
});
});
</script>
</head>
<body>
<ul id="main_menu">
<li>1</li>
<li>2</li>
<li>3</li>
</ul>
<div class="main_content">
main content
<ul></ul>
</div>
</body>
</html>
