<form action="" id="updateUserForm" name="updateUserForm">
<table width="100%" border="1" class="table1">
<tr>
<td width="30%">所在单位</td>
<td width="70%">
<input type="hidden" name="unitid" id='updateUnitId' value="${requestScope.sysUser.unitid }">
<input type="text" name="unitname" id='updateUnitName' onclick="openUnit()" value="${requestScope.sysUser.unitname }">
</td>
</tr>
<tr>
<td>所在部门</td>
<td>
<input type="hidden" name="bmid" id='updateBmId' value="${requestScope.sysUser.bmid }">
<input type="text" name="bmname" id='updateBmName' onclick="openBm()" value="${requestScope.sysUser.bmname }">
</td>
</tr>
<tr>
<td>用户名称</td>
<td>
<input type="text" name="username" id="updateUserName" value="${requestScope.sysUser.username }">
</td>
</tr>
<table>
</form>

注：不是直接获取$("#updateUnitName").val();的值，而是用updateUserForm来获取它下面的updateUnitName的值，谢谢了！!!

alert($("#updateUserForm input[id=updateUserName]").val());

如果要用name也可以

 alert($("#updateUserForm input[name=username]").val());

来自 https://zhidao.baidu.com/question/506287164.html