jquery css gradually increases the size of div_html/css_WEB-ITnose

<script type="text/javascript" src="http://www.cnblogs.com/0banana0/admin/&rdquo;http:/ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js&rdquo;"></script><script type="text/javascript">// <![CDATA[$(function(){ $("#id").click(function() {    $(this).css({      width: function(index, value) {        alert(value);        return parseFloat(value) * 1.2;      },       height: function(index, value) {          alert(value);        return parseFloat(value) * 1.2;      }    });  });});// ]]></script><div id="id" style="background: Red; width: 50px; heigth: 50px;">sa</div>

Effect Click on the red layer