Php 嵌入的youtube视频正在从聊天中删除我的信息

当我试图在回复或发送消息时激活嵌入的youtube视频时，我的php脚本中出现了一些问题

我的php脚本是：

<?php
if($_GET['u'] != $user) {


                        $messages = addslashes($_POST['message']);
                        $messages = preg_replace_callback('#(?:https?://\S+)|(?:www.\S+)|(?:\S+\.\S+)#', function($arr)
{
    if(strpos($arr[0], 'http') !== 0)
    {
        $arr[0] = 'http://' . $arr[0];
    }
    $url = parse_url($arr[0]);

    // images
    if(preg_match('#\.(png|jpg|gif)$#', $url['path']))
    {
        echo '<img src="'. $arr[0] . '" />';
    }
    // youtube
    if(in_array($url['host'], array('www.youtube.com', 'youtube.com'))
      && $url['path'] == '/watch'
      && isset($url['query']))
    {
        parse_str($url['query'], $query);
        return sprintf('<iframe width="560" height="315" src="http://www.youtube.com/embed/%s" frameborder="0" allowfullscreen></iframe>', $query['v']);
    }
    //links
    return nl2br(sprintf('<a href="%1$s">%1$s </a> ', $arr[0]));
}, $messages);

                        $to = $_GET['u'];

                        $selPictureMsg = "SELECT * FROM users WHERE username = '$user'";
                        $result = mysqli_query($sql, $selPictureMsg);
                        $msgPicRow = mysqli_fetch_assoc($result);

                        $selPictureMsg11 = "SELECT * FROM users WHERE username = '$to'";
                        $result11 = mysqli_query($sql, $selPictureMsg11);
                        $msgPicRow11 = mysqli_fetch_assoc($result11);

                        $user_pic = $msgPicRow['profile'];
                        $receiver_pic = $msgPicRow11['profile'];

                        if(isset($_POST['msgSend'])) {
                            if(strlen($messages) <= 1) {
                                echo "<div class='error'>Sorry! Your message is too small. It needs to be more than 1 character.</div>";
                            } else {

                                $insMsg = "INSERT INTO messages VALUES('','$user','$to','$messages','0','$user_pic','$receiver_pic', NOW())";
                                $sql->query($insMsg);
                                echo "<div class='success'>Your message has been sent to ".$to." successfully.</div><br />";

                            }
                        }



                    $selmsg1 = "SELECT * FROM messages WHERE (to_user='$user' AND from_user='$to') OR (to_user ='$to' AND from_user='$user') ORDER BY date DESC";
                    $resultmsg1 = $sql->query($selmsg1);
                    $rownum = mysqli_num_rows($resultmsg1);                 

                    if($rownum > 0) {
                            $i = '';
                                echo "<table>
                                            <tr class='chat'>"; 
                    while($assocMsg = mysqli_fetch_assoc($resultmsg1)) {



                        if($user == $_GET['from'] || $user != $assocMsg['to_user']) {
                              $smilies = array(
        ':|'  => 'bored',
        ':-|' => 'bored',
        ':-o' => 'scared',
        ':-O' => 'scared',
        ':o'  => 'scared',
        ':O'  => 'scared',
        ';)'  => 'wink',
        ';-)' => 'wink',
        ':p'  => 'tongue',
        ':-p' => 'tongue',
        ':P'  => 'tongue',
        ':-P' => 'tongue',
        ':D'  => 'happy',
        ':-D' => 'happy',
        ';P'  => 'wink-tongue',
        ';-P' => 'wink-tongue',
        ':)'  => 'smile',
        ':-)' => 'smile',
        ':('  => 'sad',
        ':-(' => 'sad',
        '<3' => 'heart',
        ':*' => 'kiss',
        '*_*' => 'in-love',
        ';(' => 'crying',
        ':a' => 'angry',
        ':@' => 'rage',
        ':3' => 'normal-kiss',
        '><' => 'shy',
        ';D' => 'happily',
        ';-D' => 'happily',
        ':$' => 'blushing',
        'o_o"' => 'dont-get',
        'XD' => 'laugh',
        '*lookdown*' => 'look-down',
        '*lookup*' => 'look-up',
        '*lookleft*' => 'look-left',
        '*lookright*' => 'look-right',
        '$_$' => 'money',
        '$.$' => 'money',
        '@_@' => 'nerd',
        '@.@' => 'nerd',
        '*vomit*' => 'vomit'
    );

    $replace = array();
    foreach ($smilies as $smiley => $imgName)
    {
        array_push($replace, '<img src="images/emoticons/'.$imgName.'.png" alt="'.$smiley.'" />');
    }
    $assocMsg["message"] = str_replace(array_keys($smilies), $replace, $assocMsg["message"]);
                            echo "
                                            <div style='width:100%; max-height: 300px; overflow: auto;'>
                                            <td><a href='profile.php?u=".$assocMsg['from_user']."'><img src='".$assocMsg['user_picture']."' width='auto' height='70px' /></a></td>
                                            <td>".$assocMsg['message']."<br />".$video."</td>
                                            </tr>
                                            <tr>
                                            <td colspan='5'><i>".$assocMsg['date']."</i></td>
                                            </div>
                                        ";

                                        $i++; 
                                        if($i % 1 == 0) {
                                            echo "</tr><tr class='chat'>";
                                        }
                        } else {
                            echo "
                                            <div style='width:100%; max-height: 300px; overflow: auto;'>
                                            <td><a href='profile.php?u=".$assocMsg['to_user']."<img src='".$assocMsg['friend_picture']."' width='auto' height='70px' /></a></td>
                                            <td>".$messages."</td>
                                            </tr>
                                            <tr>
                                            <td colspan='5'><i>".$assocMsg['date']."</i></td>
                                            </div>
                                        ";

                                        $i++; 
                                        if($i % 1 == 0) {
                                            echo "</tr><tr class='chat'>";
                                        }
                             }
                        }
                    echo "</tr>
                                    </table><hr />";
                    } else {
                        echo "You don't have any conversations with $to<br /><hr />";
                    }
?>