脚本在实际服务器中不起作用，但在本地主机 XAMPP 中工作

我似乎找不到问题，因为我的代码在本地主机 xampp 中工作。 但是一旦我上传到实际服务器，它就不起作用了。

没有任何错误输出

当我提交表单时，它会输出加载器，然后消失，并且没有成功消息或错误消息输出<div id="status"></div>

JavaScript：

<script>
    function _(id){ return document.getElementById(id); }
    function submitForm(){
        _("bankbtn").disabled = true;
        _("status").innerHTML = '<div class="progress"><div class="progress-bar progress-bar-striped active" role="progressbar" aria-valuenow="100" aria-valuemin="0" aria-valuemax="100" style="width: 100%"><span class="sr-only">Loading...</span></div></div><br />';
        var formdata = new FormData();
        formdata.append( "bcountry", _("bcountry").value );
        formdata.append( "bname", _("bname").value );
        formdata.append( "baname", _("baname").value );
        formdata.append( "bno", _("bno").value );
        formdata.append( "bswift", _("bswift").value );
        var ajax = new XMLHttpRequest();
        ajax.open( "POST", "editbank_engine.php" );
        ajax.onreadystatechange = function() {
            if(ajax.readyState == 4 && ajax.status == 200) {
                if(ajax.responseText == "success"){
                    _("editbank").innerHTML = '<div class="alert alert-success"><h2>Changes has been saved</h2></div>';
                } else {
                    _("status").innerHTML = ajax.responseText;
                    _("bankbtn").disabled = false;
                }
            }
        }
        ajax.send( formdata );
    }
</script>

.html

<div class="modal fade" id="edit" tabindex="-1" role="dialog">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        <h4 class="modal-title">Edit</h4>
      </div>
      <div class="modal-body">
        <form id="editbank" onsubmit="submitForm(); return false;">
        <div id="status"></div>
            <input class="form-control" type="text" value="<?php echo $bank['bank_country']?>" id="bcountry" placeholder="Bank Country" required=""/><br />
            <input class="form-control" type="text" value="<?php echo $bank['bank_name']?>" id="bname" placeholder="Bank Name" required=""/><br />
            <input class="form-control" type="text" value="<?php echo $bank['bank_accountname']?>" id="baname" placeholder="Bank Account Name" required=""/><br />
            <input class="form-control" type="text" value="<?php echo $bank['bank_no']?>" id="bno" placeholder="Bank Account No." required=""/><br />
            <input class="form-control" type="text" value="<?php echo $bank['bank_swiftcode']?>" id="bswift" placeholder="Bank Swift Code"/><br />
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <button id="bankbtn" type="submit" class="btn btn-primary">Save changes</button>
      </div>
      </form>
    </div><!-- /.modal-content -->
  </div><!-- /.modal-dialog -->
</div><!-- /.modal -->

.php

<?php
session_start();
include_once('../php/config.php');
include_once('../php/func.php');
if(
    isset($_SESSION['hotel_id']) &&
    isset($_POST['bcountry']) &&
    isset($_POST['bname']) &&
    isset($_POST['baname']) &&
    isset($_POST['bno']) &&
    isset($_POST['bswift']) &&
    !empty($_SESSION['hotel_id']) &&
    !empty($_POST['bcountry']) &&
    !empty($_POST['bname']) &&
    !empty($_POST['baname']) &&
    !empty($_POST['bno']) &&
    !empty($_POST['bswift']) 
){
    $update = $dbo->prepare('UPDATE bank_details SET bank_country=:bankcountry, bank_name=:bankname, bank_accountname=:bankaccountname, bank_no=:bankno, bank_swiftcode=:bankswift, active=0, last_updated=NOW() WHERE hid=:hid AND active = 1');
    $update->bindParam(':bankcountry', $_POST['bcountry'], PDO::PARAM_STR);
    $update->bindParam(':bankname', $_POST['bname'], PDO::PARAM_STR);
    $update->bindParam(':bankaccountname', $_POST['baname'], PDO::PARAM_STR);
    $update->bindParam(':bankno', $_POST['bno'], PDO::PARAM_STR);
    $update->bindParam(':bankswift', $_POST['bswift'], PDO::PARAM_STR);
    //$update->bindParam(':active', '0', PDO::PARAM_STR);
    $update->bindParam(':hid', $_SESSION['hotel_id'], PDO::PARAM_STR);
    $update->execute();
    if($update->rowCount() == 1){
        echo 'success';
        //echo '<div class="alert alert-success"><b>Changes has been saved</b></div>'   ;     
        //mail_log('-User '.$_SESSION['extranet_user'].' has updated his bank details at '.date(time(), 'Y/m/d H:i:s').'');
    }else{
        echo '<div class="alert alert_danger"><strong>Error has occurred, You can only update once your account has been approved</strong></div>';
        //mail_log(' User '.$_SESSION['extranet_user'].' has run into an error via bank details at '.date(time(), 'Y/m/d H:i:s').'');
    }
}
?>