下啦菜单的操作，急，谢谢大虾指点

Question

<script language="javascript">
   var obj=dtmToDay
    while(obj.length!=0)  obj.remove(0);     
</script>

Answer 1

还可以<script language="javascript">
   var obj=dtmToDay
   obj.innerHTML=""
</script>

Answer 2

<select size="1" name="dtmToDay">                  
<option value="1">1</option>                            
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select><script language="javascript">
var obj=dtmToDay
obj.length=0
</script>