PHP 多个复选框删除

我很难解决删除多个复选框的问题。有人可以指导我找到解决方案吗？这里应该发生的是，用户可以勾选复选框并单击删除按钮来删除勾选的框。不幸的是，我的代码似乎不起作用；你能为我指出正确的方向吗？

<div id="container" class="page">
        <img id="disclaimer" class="page" src="images/DISCLAIMER.png" alt="" />
        <img id="logo" class="page" src="images/MI-LOGO.png" alt="" />
        <div id="videoContainer" class="page">
            <video id="video" controls>
                <source src="video/animationTest.m4v" />
            </video>
        </div>
        <div id="etc" class="page">
            <form action="<?php echo $_SERVER['PHP_SELF']?>" method="POST">
                    <textarea name="textPost" id="textPost"> 
                    </textarea>
                        <input type="submit" name="btnPost" id="btnPost" value="Post" />
                        <div id="displayOpacity">
                            <input type="text" name="display" id="display" value="0" />
                        </div>
                        <input type="submit" value="Delete" name="btnDelete" id="btnDelete" />


        </div>
        <div id="postItDiv" class="page">
            <?php
                $cxn = mysqli_connect('localhost','root','root','TimePost')  or die(mysqli_error());
                $selectQuery = "SELECT PostID, ClientName, VideoName, PostTime, Post, Date FROM tblTimePosts";
                $selectResult = mysqli_query($cxn,$selectQuery) or die(mysqli_error());
                while($row = mysqli_fetch_assoc($selectResult)) 
                {
                    $postz = $row['Post'];
                    $timez = $row['PostTime'];
                    $idNoz = $row['PostID'];
                    echo '<div id="post1"><p class="postParagraph">Post ID No.'.$idNoz.'<br />'.$postz.' at '.$timez.' seconds mark</p><input type="checkbox" name="checkbox[]" id="checkbox[]" value="'.$idNoz.'"</input></div>';
                }
            if ($_POST['btnPost'] == "Post") {

                $toPost = $_POST['textPost'];
                $date = date("y-m-d");
                $postTime = $_POST['display'];
                $postTime = floor($postTime);

                $insertQuery = "INSERT INTO tblTimePosts VALUES ('','Mimagazine Asia','Chelsea','$postTime','$toPost','$date')";
                $insertResult = mysqli_query($cxn,$insertQuery) or die(mysqli_error());
                $query = "SELECT PostID, ClientName, VideoName, PostTime, Post, Date FROM tblTimePosts";
                $result = mysqli_query($cxn,$query) or die(mysqli_error());
                while($row = mysqli_fetch_assoc($result)) 
                {
                    $post = $row['Post'];
                    $time = $row['PostTime'];
                    $idNo = $row['PostID'];
                    echo '<div id="post1"><p class="postParagraph">Post ID No.'.$idNo.'<br />'.$post.' at '.$time.' seconds mark</p><input type="checkbox" name="checkbox[]" id="checkbox[]" value="'.$idNo.'"</input></div>';
                }
            }
            else if($_POST['btnDelete'] == "Delete")
            {
               $tbl_name = 'tblTimePosts';
               foreach ($_POST['checkbox'] as $id => $value) 
               {
                  $sql = 'DELETE FROM `'.$tbl_name.'` WHERE `PostID`='.(int)$id;
                  $resulta = mysqli_query($cxn,$sql);
                  if ($resulta > 0) {
                                echo "success";
                            }
                            else
                                echo "fail";
                        }
                        header('Location: videoJudge.php'); 
                 }
            ?>
            </form>
        </div>

            <span id="copyright" class="page">Copyright © 2011<span style="color:#00AEEF;">mi</span>magazine.asia</span>
            <span id="comment" class="page" style="color:#00AEEF;">comment/s</span>
            <span id="download" class="page">(Right-click to download video)</span>
    </div>

这个 HTML：

echo '<div id="post1"><p class="postParagraph">Post ID No.'.$idNoz.'<br />'.$postz.' at '.$timez.' seconds mark</p><input type="checkbox" name="checkbox[]" id="checkbox[]" value="'.$idNoz.'"</input></div>';

应该：

echo '<div id="post1"><p class="postParagraph">Post ID No.'.$idNoz.'<br />'.$postz.' at '.$timez.' seconds mark</p><input type="checkbox" name="checkbox[]" id="checkbox[]" value="'.$idNoz.'" /></div>';

此查询于else if($_POST['btnDelete'] == "Delete")应该：

$sql = 'DELETE FROM `'.$tbl_name.'` WHERE `PostID`='.(int)$value;