我正在尝试创建一个下拉列表，其中范围编号将取决于cm名称。我已经尝试过并尝试了我的代码，每次运行它时，我都可以选择cm名称，但是范围编号框不允许我选择任何范围编号。有什么建议吗？
<body>
<form action="submitform.asp" method="post" name="tipinvestmentsemiannualprogressform " id="tipinvestmentsemiannualprogressform ">
<h2>TIP Investment Semi-Annual Progress Form</h2>
<table width="50% " border="0 " cellspacing="0 " cellpadding="5 ">
<tr>
<td width="41% " align="right " valign="middle ">CM Name :</td>
<td width="59% " align="left " valign="middle ">
<select name="cmname " id="cmname ">
<option value=" ">Select CM Name</option>
<option value="p_c ">P C</option>
<option value="g_g ">G G</option>
<option value="b_h ">B H</option>
<option value="b_h ">S H</option>
<option value="k_k ">K K</option>
<option value="j_l ">J L</option>
<option value="e_l ">E L</option>
<option value="r_t ">R T</option>
</select>
</td>
</tr>
<tr>
<td align="right " valign="middle ">Scope Number :</td>
<td align="left " valign="middle ">
<select disabled="disabled " id="scopenumber " name="scopenumber ">
<option class="label " value>Select Scope Number</option>
<!-- P C -->
<option rel="p_c " value="black ">black</option>
<!-- G G-->
<option rel="g_g " value="red ">red</option>
<!-- B H -->
<option rel="b_h " value="orange ">orange</option>
<!-- S H -->
<option rel="s_h " value="yellow ">yellow</option>
<!-- K K -->
<option rel="k_k " value="green ">green</option>
<!-- J L -->
<option rel="j_l " value="blue ">blue</option>
<!-- E L -->
<option rel="e_l " value="indigo ">indigo</option>
<!-- R T -->
<option rel="r_t " value="violet ">violet</option>
</select>
</td>
</tr>
</table>
</form>
</body>
<script src="//code.jquery.com/jquery-1.11.2.min.js"></script>
<script>
$(function()) {
var $cat = $("#cmname"),
$subcat = $("#scopenumber");
$cat.on("change", function()) {
var _rel = $(this).val();
$subcat.find("option").attr("style", "");
$subcat.val("");
if (!_rel) return $subcat.prop("disabled", true);
$subcat.find("[rel=" + _rel + "]").show();
$subcat.prop("disabled", false);
});
});
</script>
答案 0 :(得分：-1)
我想你想改变这一行：
$subcat.find("[rel=" + _rel + "]").show();
为：
$subcat.find("[rel=" + _rel + "]").prop('selected', true);