提交按钮之后无法显示模式10秒钟，然后导航到另一个页面

Question

在我的应用中，我希望在提交表单时显示模式或弹出窗口10到15秒，然后导航到另一个页面。

<td colspan=3><button class="btn btn-success btn-lg btn-block" id="submit" type="submit">ADD TOPIC</button></td>

模式：

<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="memberModalLabel" aria-hidden="true">
<div class="modal-dialog">
    <div class="modal-content">
        <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">&times;</span><span class="sr-only">Close</span></button>
            <h4 class="modal-title" id="memberModalLabel">Edit Member Detail</h4>
        </div>
        <div class="modal-body">
            <p>Success</p>
        </div>

    </div>
</div>
</div>

Ajax：

<script>
    $(document).ready(function(){
        $('#submit').click(function(){
            var txttopicname = $('#txttopicname').val();
            var boardid = $('#boardid').val();
            var bclassid = $('#bclassid').val();
            var subjectid = $('#subjectid').val();

            if(txttopicname == '' )  
            {  
              $('#error_message').html("All Fields are required");  
            }
            else{
                $('#error_message').html('');
                $.ajax({
                    url: "topicadddb.php", 
                    method: "POST",
                    data: {txttopicname:txttopicname, boardid:boardid, bclassid:bclassid, subjectid:subjectid},
                    success:function(data){
                        $('#myModal').modal('show').html(data);
                        setTimeout(function(){
                            $('#myModal').modal('hide');
                        },10000);
                        window.location="topiclistdb.php"; //navigate
                    }
                });
            }

        });
    });
</script>

topicadddb.php：

<?php
 if (isset($_POST['txttopicname'])) {
    $topicname  = $_POST['txttopicname'];

    $boardid = $_POST['boardid'];

    $bclassid = $_POST['bclassid'];

    $subjectid = $_POST['subjectid'];

    $s="INSERT INTO topicinfo (topicname,boardid,bclassid,subjectid,status) VALUES ( UPPER('$topicname'),'$boardid','$bclassid','$subjectid',0)";

//echo $s;

    mysqli_query($conn,$s) or die( mysqli_error());
    header('Location:topiclistdb.php');
}
?>

当我单击“提交”按钮时，它会淡出1秒钟，然后直接转到下一页。