表单加载空白页，提交后无法发送电子邮件

所以我刚刚把我的网站的所有内容都放到了网上，我已经把所有内容都设置成了我认为正确的。。但由于某种原因，在表单提交后，它只是加载"send_form_email.php"页面，给网站访问者一个空白页面。。此外，我似乎没有收到发送到收件箱的电子邮件。。我想不出哪里出了问题。。我猜是HTML吗？

这是表单的HTML代码，如果你需要查看整个网页，请告诉我HTML:

    <!-- form -->
            <form name="contactform" id="contactform" method="post" action="send_form_email.php">
             <fieldset>
                <legend class="lined">Pre-Register for free!</legend>
                <label for="pname">Name</label>
                <input name="pname" id="pname" value="" type="text">
                <label for="pemail">Email</label>
                <input name="pemail" id="pemail" value="" type="text">
                <label for="company">Business Name</label>
                <input name="company" id="company" value="" type="text">
                <label for="comment">Where do you offer your services?</label>
                <textarea name="comments" id="comments"></textarea>
              </fieldset>    
              <input type="submit" value="Submit">
            </form><!-- /form -->

这里是PHP代码（文件名send_form_email.PHP）；

<?php
if(isset($_POST['pemail'])) {
// EDIT THE 2 LINES BELOW AS REQUIRED
$email_to = 'info@whichpt.com';
$email_subject = 'Pre-Registration Submission';

function died($error) {
    // your error code can go here
    echo 'We are very sorry, but there were error(s) found with the form you submitted. ';
    echo 'These errors appear below.<br /><br />';
    echo $error.'<br /><br />';
    echo 'Please go back and fix these errors.<br /><br />';
    die();
}
// validation expected data exists
if(!isset($_POST['pname']) ||
    !isset($_POST['pemail']) ||
    !isset($_POST['company']) ||
    !isset($_POST['comments'])) {
    died('We are sorry, but there appears to be a problem with the form you submitted.');       
}
$pname = $_POST['pname']; // required
$pemail = $_POST['pemail']; // required
$company = $_POST['company']; // not required
$comments = $_POST['comments']; // required
$error_message = '';
$email_exp = '/^[A-Za-z0-9._%-]+@[A-Za-z0-9.-]+'.[A-Za-z]{2,4}$/';
if(!preg_match($email_exp,$pemail)) {
$error_message .= 'The Email Address you entered does not appear to be valid.<br />';
}
$string_exp = '/^[A-Za-z .'-]+$/';
if(!preg_match($string_exp,$pname)) {
$error_message .= 'The Name you entered does not appear to be valid.<br />';
}
if(strlen($comments) < 2) {
$error_message .= 'The location of services information you entered do not appear to be valid.<br />';
}
if(strlen($error_message) > 0) {
died($error_message);
}
$email_message = 'Form details below.'n'n';
function clean_string($string) {
  $bad = array('content-type','bcc:','to:','cc:','href');
  return str_replace($bad,'',$string);
}
$email_message .= 'Name: '.clean_string($pname).''n';
$email_message .= 'Email: '.clean_string($pemail).''n';
$email_message .= 'Business: '.clean_string($company).''n';
$email_message .= 'Comments: '.clean_string($comments).''n';

// create email headers
$headers = 'From: '.$pemail.''r'n'.
'Reply-To: '.$pemail.''r'n' .
'X-Mailer: PHP/' . phpversion();
@mail($email_to, $email_subject, $email_message, $headers);  
?>
<!-- include your own success html here -->
Thank you for contacting us. We will be in touch with you very soon.
<?php
}
?>