JavaScript动态修改网页元素的内容

下面的JS代码当用户点击提交按钮后，通过元素的textContent或者innerHTML动态指定元素的内容

<script type="text/javascript">
function showCard() {
 var message = document.getElementById("CCN").value;
 var element = document.getElementById("mycreditcardnumber");
  element.textContent  = message; //for Firefox
  element.innerHTML  = message; //for IE (why can't we all just get along?)
  return true;
}
</script>
<form name="dynamic" method="get">
<span>Enter Your Credit Card Number:</span>
<input type="text" id="CCN" name="CCN" value="CCN" />
<input type="button" value="submit" onclick="showCard()" />
</form>

<p>Verify your Credit Card Number: 
  <span id="mycreditcardnumber">0000-00-0000-00 </span>
</p>