JavaScript实现网页多级级联菜单

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>多级级联菜单</title>
<script type="text/javascript">
var arr2 = new Array(4);
arr2["数码设备"] = new Array("数码相机","打印机");
arr2["家用电器"] = new Array("电视机","电冰箱");
arr2["礼品工艺"] = new Array("鲜花","彩带");
function removeinfo(classMenu){//将下拉框各选项清空
 for (var i=0; i < classMenu.options.length; i++){
 classMenu.options[i]=null;
 }
}
function changeMenu(classList,classMenu){
 removeinfo(classMenu)
 for (var i=0; i < classList.length; i++){
 classMenu[i]=new Option(classList[i],classList[i]);
 }
}
</script>
</head>
<body style="font-size:12px">
<table width="487" height="333" border="0" align="center" cellpadding="0" cellspacing="0">
 <tr>
 <td align="center" valign="top"><br>
 <br>
 <br>
 <br> <br> <table width="86%" border="0" align="center" cellpadding="2" cellspacing="1" bgcolor="#6699CC">
 <form name="form1">
 <tr bgcolor="#FFFFFF">
  <td height="22" align="right">所属类别:</td>
  <td height="22" align="left"><select name="类别" id="类别" onChange="changeMenu(arr2[document.form1.类别.options[document.form1.类别.selectedIndex].text],document.form1.分类);">
  <option selected>数码设备</option>
  <option>家用电器</option>
  <option>礼品工艺</option>
  </select>
  <select name="分类" id="分类">
  <option>数码相机</option>
  <option>打印机</option>
  </select></td>
 </tr>
 <tr bgcolor="#FFFFFF">
  <td height="22" align="right">商品名称:</td>
  <td height="22" align="left"><input name="商品名称" type="text" id="商品名称" size="30" maxlength="50"></td>
 </tr>
 <tr bgcolor="#FFFFFF">
  <td height="22" align="right">会员价:</td>
  <td height="22" align="left"><input name="会员价" type="text" id="会员价" size="10"></td>
 </tr>
 <tr bgcolor="#FFFFFF">
  <td height="22" align="right">提供厂商:</td>
  <td height="22" align="left"><input name="提供厂商" type="text" id="提供厂商" size="30" maxlength="50"></td>
 </tr>
 <tr bgcolor="#FFFFFF">
  <td height="22" align="right">商品简介:</td>
  <td height="22" align="left"><textarea name="商品简介" cols="35" rows="4" id="商品简介"></textarea></td>
 </tr>
 <tr bgcolor="#FFFFFF">
  <td height="22" align="right">商品数量:</td>
  <td height="22" align="left"><input name="商品数量" type="text" id="商品数量" size="10"></td>
 </tr>
 <tr bgcolor="#FFFFFF">
  <td height="22" colspan="2" align="center"><input name="add" type="submit" id="add2" value="添 加">
&nbsp;
 <input type="reset" name="Submit2" value="重 置"></td>
 </tr>
 </form>
 </table></td>
 </tr>
</table>
</body>
</html>