set/getAttribute()

你好，我想问一下在下面的代码中，怎样设置属性:setAttribute

    <div id='d1'>test1</div>
    <script type="text/javascript">
     function test(){
       var prop = document.getElementById('d1')
           alert(prop.getAttribute('id'))
           prop.setAttribute()
         }
</script>

谢谢

---

<div id='d1'>test1</div>
<script type="text/javascript">
function test(){
    var prop = document.getElementById('d1')
    alert(prop.getAttribute('id'))
    prop.setAttribute('属性名', '属性值');
    alert(prop.getAttribute('属性名'));
}
test();
</script>