[Deff]

<script src="http://code.jquery.com/jquery-latest.js"></script>




<div class="ajax_news">1a</div>
<div class="ajax_news">2b</div>
<div class="ajax_news">3c</div>

<script type="text/javascript">
$(document).ready(function(){
  $("div.ajax_news").each(function(){
      var a=$(this);
      a.attr('id',a.text());
  });
});
</script>