js点击文本框内容互换代码

js代码

<script type="text/javascript">
 function change(){
	 
	 
  var num1 = document.getElementById("num1").value;
  var num2 = document.getElementById("num2").value;
{
   document.getElementById("num2").value = num1;
   document.getElementById("num1").value = num2;
  }
 }
</script>