多個DIV顯示/隱藏

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>無標題文檔</title>
<script type="text/JavaScript">
function jsd(a){
 var demo = document.getElementById("demo");
 var divArray = demo.getElementsByTagName("div");
 for (var i=0;i<divArray.length;i++) {
  if (divArray[i].id == a) {
   divArray[i].style.display='';
  }else {
   divArray[i].style.display='none';
  }
 }
}
</script>
</head>

<body>
   <div id="demo">
      <div id="demo1">
         <table width="200" border="1" bgcolor="#FFCC99">
  <tr>
    <td>&nbsp;</td>
 <td>&nbsp;</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
 <td>&nbsp;</td>
  </tr>
</table>
   </div>
  
   <div id="demo2"  style="display:none">
  <table width="200" border="1" bgcolor="#CC9999">
  <tr>
    <td>&nbsp;</td>
 <td>&nbsp;</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
 <td>&nbsp;</td>
  </tr>
</table>
   </div>
  
    <div id="demo3" style="display:none">
   <table width="200" border="1" bgcolor="#00CCCC">
  <tr>
    <td>&nbsp;</td>
 <td>&nbsp;</td>
  </tr>
  <tr>
    <td>&nbsp;</td>
 <td>&nbsp;</td>
  </tr>
</table>
    </div>
   
    <select name="selId" onchange="jsd(this.value)">
      <option value="demo1">0</option>
      <option value="demo2">1</option>
      <option value="demo3">2</option>      
    </select>

   </div>
</body>
</html>