如何实现隐藏select

Question

document.form.XUN.style.visibility="hidden";

Answer 1

<div id="x">
<select size=1 name="XUN" >
<option value="1" >上</option>
<option value="2" >中</option>
<option value="3" >下</option>
</select>旬
</div><script>
function a(){
  if(document.all.x.style.visibility=="hidden")
  {
     document.all.x.style.visibility="visible";
  }else{
     document.all.x.style.visibility="hidden";
  }
}
</script>
<input type=button value="显示/隐藏" onclick="a()">

Answer 2

function a(){
  if(document.all.x.style.display=="none")
  {
     document.all.x.style.display="block";
  }else{
     document.all.x.style.display="none";
  }
}