Issue with Jquery Code while Content is loaded through ajax

Hi, I have the following code where i am making an ajax to the external page andoing it like this

<script>
$(document).ready(function(){
  $("button").click(function(){
    $.ajax({
              url:"demo_test.txt",
              success:function(html){
              source = $("#code").html();
              template = Handlebars.compile(source);
              $('#list').html(template(response));
    }});
  });
});
</script>

Now there a element which is called as

<div id="list"></div>

The response coming from the jquery is loaded in that div inside it,

so i want to apply a class to the internal code but it is nt reflecting, if itry to add the straight css property, it works but not the class, even i have defined the class in the css file