我一直在研究stackoverflow的答案，但找不到一个可以帮助我解决这个问题。
我有一个通过ajax加载的表单，其中输入嵌套在一个表中。我试图将数据发布到db中，但是输入值总是被读取为空。
html表单：

<form method="POST" action="index.php" id="clientsubmitform">
   <table class="table table-responsive col-md-6 col-lg-6 form-group">
      <thead>
         <tr>
            <th></th>
            <th>First Name</th>
            <th>Last Name</th>
            <th>Phone Number</th>
            <th>Status</th>
            <th>Lead Type</th>
         </tr>
      </thead>
      <tbody>
         <tr>
            <td><input type="hidden" name="clientid[]" value="26" form="clientsubmitform"></td>
            <td><input type="text" class="clientfirstname" name="clientfirstname[]" value="Robert" form="clientsubmitform" readonly></td>
            <td><input type="text" class="clientlastname" name="clientlastname[]" value="DeNiro" form="clientsubmitform" readonly></td>
            <td><input type="text" class="clientphonenumber" name="clientphonenumber[]" value="0987654321" form="clientsubmitform" readonly></td>
            <td id="statustd">
               <select id="status" name="statusselect[]" form="clientsubmitform">
                  <option> </option>
                  <option value="1" class="status">Answered</option>
                  <option value="2" class="status">No Answer</option>
                  <option value="3" class="status">Busy</option>
                  <option value="4" class="status">Call Back</option>
                  <option value="5" class="status">Wrong Number</option>
                  <option value="6" class="status">Lead</option>
                  <option value="7" class="status">Indian</option>
               </select>
            </td>
            <td id="islead" style="display: none;">
               <select class="isleadgrade" name="isleadselect[]" form="clientsubmitform">
                  <option>Lead Type</option>
                  <option value="1">Cold  Lead</option>
                  <option value="2">Warm Lead</option>
                  <option value="3">Hot Lead!</option>
               </select>
            </td>
         </tr>
      </tbody>
   </table>
   <br><input type="button" class="btn btn-task col-md-8 col-lg-8 offset-lg-1 offset-md-1" id="clientsubmit" name="clientsubmit" value="SUBMIT" form="clientsubmitform">
</form>

php函数：

global $db;
    global $data;
    if($_SERVER['REQUEST_METHOD'] == "POST") :
    $userid = $_SESSION['login_user_id'];
    $clientid = isset($_POST['clientid']) != '' ? $_POST['clientid'] : array();
    for($i = 0; $i <= count($clientid); $i++) {
        $status = isset($_POST['statusselect']) != '' ? $_POST['statusselect'][$i] : NULL;
        $leadtype = isset($_POST['isleadselect']) != '' ? $_POST['isleadselect'][$i] : NULL;
        $clientid = isset($_POST['clientid']) != '' ? $_POST['clientid'][$i] : NULL;
        $query = "UPDATE clients SET status = '$status', leadtype = '$leadtype' WHERE id = '$clientid' AND agent_assigned = '$userid'";
        $result = mysqli_query($db, $query);
        return true;
    }
    endif;

来自php函数的数据被传递到ajax\u响应函数，该函数触发成功或失败。post成功，但值仍为空。
提前谢谢大家！