jquery在一个标签前加一个标签 jquery给a标签添加href

<script type="text/javascript">
function doTest(){

	var value = $("input[name='dizhi'][type='radio']:checked").val();//获得选中项的值
	$('#a1').attr('href','shoppeisong.php?addid='+value+''); 
  }
</script>

要取的INPUT 标签<input name="dizhi" type="radio" id="dizhi" onclick="doTest()" value="<?php echo $rsaddress['id'];?>" />

赋值到

<a id="a1" href="" class="bt" onclick="xx()">　下一步　</a>