即使单击提交按钮后仍保持引导模式处于活动状态

Question

点击提交按钮后，帮我找到保持模态激活的方法。提前致谢。点击提交后，重新加载页面。 更新 这是我的代码我已经在模板的div页脚之后插入了我的php代码，所以当它无法插入或其他文本框为空时显示以下错误

<div class="modal fade" id="addtopic" role="dialog">
    <div class="modal-dialog">

        <div class="modal-content">
                <div class="modal-header">
                    <h4>Add Topic</h4>
                </div>
                <form method="POST" action="index.php" role="form">
                <div class="modal-body">

                          <div class="form-group">
                            <label for="cCategory">Category</label>
                            <input type="text" class="form-control" id="cCategory" name="category" value="<?php if (!empty($categ)) { echo $categ; }  ?>">
                          </div>        

                        <div class="form-group">
                            <label for="cTitle">Title</label>
                            <input type="text" class="form-control" id="cTitle" name="topicTitle" value="<?php if (!empty($topicTitle)) { echo $topicTitle; }  ?>">
                          </div>

                          <div class="form-group">
                            <label for="cDesc">Description</label>
                            <textarea class="form-control custom-control" rows="3" style="resize:none" name="desc" value="<?php if (!empty($desc)) { echo $desc; }  ?>"> </textarea>
                          </div>

                          <div class="form-group">
                            <label for="cDesc">Created By</label>
                            <input type="text" class="form-control" id="cDesc" name="createdby" value="<?php if (!empty($created)) { echo $created; }  ?>">
                          </div>

                </div>

                <div class="modal-footer">

                                  if(!empty($_POST['desc']) && !empty($_POST['category']) && !empty($_POST['topicTitle']) && !empty($_POST['createdby']))   {
                            $desc = $_POST['desc'];
                            $categ = $_POST['category'];
                            $topicTitle = $_POST['topicTitle'];
                            $created = $_POST['createdby'];

                                    if($insert = $db->query("
                                     INSERT INTO pncontent (category, title, description, createdby, dateadded)
                                     VALUES ('$categ', '$topicTitle', '$desc', '$created', NOW() )
                                    ")) {
                                        echo "<p class='pull-left'> Topic Save! </p>";
                                    }else {
                                        echo "<p class='pull-left'>Failed to Save</p>";

                                            die($db->error);

                                    }

                                }else {
                                    echo "<p class='pull-left'>All Fields are required</p>";
                                            $desc = $_POST['desc'];
                                            $categ = $_POST['category'];
                                            $topicTitle = $_POST['topicTitle'];
                                            $created = $_POST['createdby'];

                                }

                            }
?>                  
                <button type="submit" name="Sbt" class="btn btn-primary" >Save changes</button>
                  <button data-dismiss="modal"  class="btn btn-danger">Close</button>

                </form>

            </div>
        </div>

    </div>
</div>