Javascript 引导模式注册不工作

我有这个密码

  <form id="form" role="form" method="post" action="" autocomplete="off" enctype="multipart/form-data">

<!-- Modal -->
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
  <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" id="myModalLabel">Modal title</h4>
      </div>
      <div class="modal-body">




                <?php
                // Verificar erros
                if(isset($error)){
                    foreach($error as $error){
                        echo '<p class="register-errors">'.$error.'</p>';
                    }
                }

                // Mensagem de sucesso
                if(isset($_GET['action']) && $_GET['action'] == 'joined'){
                    echo "<h2 class='register-sucess'>Registration successful, please check your email to activate your account.</h2> ";
                }
                ?>


    <input type="text" name="username" id="username" class="register-username" placeholder="Username" value="<?php if(isset($error)){ echo $_POST['username']; } ?>" tabindex="1" maxlength="12">


    <br>
    <img id="uploadPreview1" src="../cdn/css/images/no_image.jpg" width="130" height="130"/>

    <input id="uploadImage1" type="file" name="img[]" onchange="PreviewImage(1);" />
           <label for="uploadImage1" >Add profile picture</label>


    <br>



    <input type="email" name="email" id="email" class="register-email" placeholder="Email Address" value="<?php if(isset($error)){ echo $_POST['email']; } ?>" tabindex="2">

    <br>

    <input type="password" name="password" id="password" class="register-password" placeholder="Password" tabindex="3">
    <input type="password" name="passwordConfirm" id="passwordConfirm" class="register-confirmpassword" placeholder="Confirm Password" tabindex="4">

    <br>


    <br>







<?  



if(isset($_POST['submit'])){


        if(strlen($_POST['username']) < 3){
            $error[] = 'Username is too short.';
        } else {
            $stmt = $db->prepare('SELECT username FROM members WHERE username = :username');
            $stmt->execute(array(':username' => $_POST['username']));
            $row = $stmt->fetch(PDO::FETCH_ASSOC);

            if(!empty($row['username'])){
                $error[] = 'Username provided is already in use.';
            }
        }

        if(strlen($_POST['password']) < 3){
            $error[] = 'Password is too short.';
        }

        if(strlen($_POST['passwordConfirm']) < 3){
            $error[] = 'Confirm password is too short.';
        }

        if($_POST['password'] != $_POST['passwordConfirm']){
            $error[] = 'Passwords do not match.';
        }

        if(!filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)){
            $error[] = 'Please enter a valid email address';
        } else {
            $stmt = $db->prepare('SELECT email FROM members WHERE email = :email');
            $stmt->execute(array(':email' => $_POST['email']));
            $row = $stmt->fetch(PDO::FETCH_ASSOC);

            if(!empty($row['email'])){
                $error[] = 'Email provided is already in use.';
            }

        }


        if(!isset($error)){

            // Proteger a password
            $hashedpassword = $user->password_hash($_POST['password'], PASSWORD_BCRYPT);

            // Criar código de activação
            $activasion = md5(uniqid(rand(),true));

            try {

        $file       = $_FILES['img'];
        $numFile    = count(array_filter($file['name']));

        //PASTA
        $folder     = '../cdn/uploads/avatars/';

        //REQUISITOS
        $permite    = array('image/jpeg', 'image/png');
        $maxSize    = 1024 * 1024 * 1;

        //MENSAGENS
        $msg        = array();
        $errorMsg   = array(
        1 => 'O arquivo no upload é maior do que o limite definido em upload_max_filesize no php.ini.',
        2 => 'O arquivo ultrapassa o limite de tamanho em MAX_FILE_SIZE que foi especificado no formulário HTML',
        3 => 'o upload do arquivo foi feito parcialmente',
        4 => 'Não foi feito o upload do arquivo'
            );

    if($numFile <= 0){
        echo '<script>alert(asd);</script>';
    }
    else{
        for($i = 0; $i < $numFile; $i++){
        $name   = $file['name'][$i];
        $type   = $file['type'][$i];
        $size   = $file['size'][$i];
        $error  = $file['error'][$i];
        $tmp    = $file['tmp_name'][$i];

        $extensao = @end(explode('.', $name));
        $avatar = rand().".$extensao";

        if($error != 0)
            $msg[] = "<b>$name :</b> ".$errorMsg[$error];
        else if(!in_array($type, $permite))
            $msg[] = "<b>$name :</b> Erro imagem não suportada!";
        else if($size > $maxSize)
            $msg[] = "<b>$name :</b> Erro imagem ultrapassa o limite de 1MB";
        else{

        if(move_uploaded_file($tmp, $folder.'/'.$avatar)){


                $stmt = $db->prepare('INSERT INTO members (username,password,email,active,avatar) VALUES (:username, :password, :email, :active, :avatar)');
                $stmt->execute(array(
                    ':username' => $_POST['username'],
                    ':password' => $hashedpassword,
                    ':email' => $_POST['email'],
                    ':active' => $activasion,
                    ':avatar' => $avatar
                ));


     }else{
     $msg[] = "<b>$name :</b> Desculpe! Ocorreu um erro...";

       }
      }
     }
     }

                // Inserir dados na base de dados

                $id = $db->lastInsertId('memberID');

                // Estrutura do email
                $to = $_POST['email'];
                $subject = " Registration Confirmation";
                $body = "Thank you for registering at site.\n\n To activate your account, please click on this link:\n\n ".DIR."activate.php?x=$id&y=$activasion\n\n\n Regards,\n Administration \n\n";
                $additionalheaders = "From: <".SITEEMAIL.">\r\n";
                $additionalheaders .= "Reply-To: ".SITEEMAIL."";
                mail($to, $subject, $body, $additionalheaders);

                header('Location: register.php?action=joined');
                exit;

            } catch(PDOException $e) {
                $error[] = $e->getMessage();
            }

        }

    }


?>

      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        <input type="submit" name="submit" value="Register" class="btn btn-primary" tabindex="5">
        </form>
      </div>
    </div>
  </div>
</div>

发生的情况是，当我提交时，它不会在数据库中添加任何内容，只会刷新页面。同样，在Ajax/jQuery中出现错误时，提交后不必刷新页面。电子邮件错误、用户等。。作为阿凡达，所以有错误，但不出现：党卫军

---

简而言之，我想帮助修复不去数据库的部分，并显示所有错误，包括阿凡达。所有这些都在ajax中发布，而不必刷新页面。

这有很多问题，但主要问题是您没有使用任何东西通过ajax发布，因此是的，页面将在提交时重新加载。第二个主要问题是，处理表单的PHP代码位于输出代码之后，因此在您告诉表单显示错误后，它才会运行。至少将您的PHP移动到页面顶部，使其以正确的顺序执行，然后您可以使用JQuery或其他工具连接AJAX帖子。您能帮我做一下吗？：ss我是新手：ss