jquery提交联系表格

I'm trying to hide the form and show the success alert after the mail is mailed.

But everything I do, is ignored by the code, I put header before the mail function, and the mail still sends, it should redirect before the mail sends, tried to break the code before the mail function, and the break functions works. at list the mail doesn't send.

contact.php:

<div id="innerWrapper">
    <h1 class="pageheading"><?=translate('contact_us') ?></h1>
    <form class="form-horizontal" action="/ajax/contact.php" method="POST" id="contactForm">
        <?php $email = $db->get_row("SELECT email,full_name FROM users WHERE userID = 1");?>
        <label><?=translate('your_name') ?>:</label> 
        <input type="text" name="name" <?php if($usersObject->ID()) {echo 'value = "'. $email->full_name. '"';} else {echo 'placeholder = "First / Last"';}?> class="required input-xlarge"/>
        <br/><br/>
        <label><?=translate('email') ?>:</label> 
        <input type="email" name="email" <?php if($usersObject->ID()) {echo 'value = "'. $email->email . '"';} else {echo 'placeholder = "email@example.com"';}?> class="required input-xlarge"/>
        <br/><br/>
        <label>Subject:</label> 
        <input type="text" name="<?=translate('subject') ?>" placeholder="Hi" class="required input-xlarge"/>
        <br/><br/>
        <label><?=translate('message') ?>:</label> 
        <textarea name="message_to_us" class="input-xlarge required" rows="5" placeholder=""></textarea>
        <br/><br/>
        <input class="btn btn-large btn-warning" value="<?=translate('contact_btn') ?>" type="submit" name="sbc"/>
    </form>
</div>

ajax/contact.php :

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

foreach($_POST as $K=>$V) $_POST[$K] = trim(strip_tags($V));
extract($_POST);

foreach($_POST as $k=>$v) {
    if(trim($v) == "") 
    {
        print '<div class="alert alert-error">All fields are required</div>';
        exit;
    }
}

$body = 'New contact form message on ' . $_SERVER['SERVER_NAME'];
$body .= '<br/>';
$body .= 'Subject : ' . $Subject;
$body .= '<br/>';
$body .= 'Name : '.$name .' / Email : ' . $email;
$body .= '<br/>';
$body .= $message_to_us;

$headers = "From: contact@" . str_replace("www.", "", $_SERVER['SERVER_NAME']) . "
";
$headers .= "Reply-To: ". $email . "
";
$headers .= "MIME-Version: 1.0
";
$headers .= "Content-Type: text/html; charset=utf-8
";

mail(PAYPAL_EMAIL, str_replace("www.", '', $_SERVER["SERVER_NAME"]), $body, $headers);


?>
<script type="text/javascript">
$("#sbc").click(function() {
    $("#contactForm").hide('slow');
});
</script>
<?php
    print '<div class="alert alert-success">'.translate('thankyou_contact').'</div>';
}else{
    print 'Emtpy request';
}

edit:

$headers .= "Content-Type: text/html; charset=utf-8
";
header('Location: join');
mail(PAYPAL_EMAIL, str_replace("www.", '', $_SERVER["SERVER_NAME"]), $body, $headers);

tried to redirect before the mail just to check, but it just ignores the header and still mail the mail.

edit2 :

<script type="text/javascript">
    $(document).ready (function() {
        $("#sbc").click(function() {
            $("#contactForm").hide('slow');
        });
    });
    </script>

not working.

add id= sbc to

 <input class="btn btn-large btn-warning" value="<?=translate('contact_btn') ?>" type="submit" name="sbc" id="sbc"/>