刷新也保留下拉框状态的例子:
<style>  
   .userData  {behavior:url(#default#userdata);}  
</style><select id="select1" class="userData">  
 <option>option1</option>  
 <option>option2</option>  
 <option>option3</option>  
 <option>option4</option>  
</select>  <script language=javascript>
function saveSelectedIndex()
{
    obj.setAttribute("sSelectValue",obj.selectedIndex);  
    obj.save("oSltIndex");  
}
function loadSelectedIndex()
{  
    obj.load("oSltIndex");  
    obj.selectedIndex=obj.getAttribute("sSelectValue");  
}
var obj=document.all.select1;  
    obj.attachEvent('onchange',saveSelectedIndex);
    window.attachEvent('onload',loadSelectedIndex)  
</script>