PHP contact form will not submit - php

Question

I have a simple php contact form i got from a web tutorial. It worked yesterday, but will not work today. I'd love some help, as I don;t know much php.
php:
<?php
//If the form is submitted
if(isset($_POST['submit'])) {
//Check to make sure that the name field is not empty
if(trim($_POST['contactname']) == '') {
$hasError = true;
} else {
$name = trim($_POST['contactname']);
}
//Check to make sure that the subject field is not empty
if(trim($_POST['subject']) == '') {
$hasError = true;
} else {
$subject = trim($_POST['subject']);
}
//Check to make sure sure that a valid email address is submitted
if(trim($_POST['email']) == '') {
$hasError = true;
} else if (!filter_var( trim($_POST['email'], FILTER_VALIDATE_EMAIL ))) {
$hasError = true;
} else {
$email = trim($_POST['email']);
}
//Check to make sure comments were entered
if(trim($_POST['message']) == '') {
$hasError = true;
} else {
if(function_exists('stripslashes')) {
$comments = stripslashes(trim($_POST['message']));
} else {
$comments = trim($_POST['message']);
}
}
//If there is no error, send the email
if(!isset($hasError)) {
$emailTo = 'person#domain.com'; // Put your own email address here
$body = "Name: $name \n\nEmail: $email \n\nSubject: $subject \n\nComments:\n $comments";
$headers = 'From: My Site <'.$emailTo.'>' . "\r\n" . 'Reply-To: ' . $email;
mail($emailTo, $subject, $body, $headers);
$emailSent = true;
}
}
?>
HTML:
<form role="form" method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>" id="contactform">
<?php if(isset($hasError)) { //If errors are found ?>
<p class="alert alert-danger">Please check if you've filled all the fields with valid information and try again. Thank you.</p>
<?php } ?>
<?php if(isset($emailSent) && $emailSent == true) { //If email is sent ?>
<div class="alert alert-success">
<p><strong>Message Successfully Sent!</strong></p>
<p>Thank you for using our contact form, <strong><?php echo $name;?></strong>! Your email was successfully sent and we’ll be in touch with you soon.</p>
</div>
<?php } ?>
<div class="form-group">
<label for="name">Your Name<span class="help-required">*</span></label>
<input type="text" name="contactname" id="contactname" value="" class="form-control required" role="input" aria-required="true" />
</div>
<div class="form-group">
<label for="email">Your Email<span class="help-required">*</span></label>
<input type="text" name="email" id="email" value="" class="form-control required email" role="input" aria-required="true" />
</div>
<div class="form-group">
<label for="subject">Subject<span class="help-required">*</span></label>
<input type="text" name="email" id="subject" class="form-control required" role="input" aria-required="true">
</div>
<div class="form-group">
<label for="message">Message<span class="help-required">*</span></label>
<textarea rows="8" name="message" id="message" class="form-control required" role="textbox" aria-required="true"></textarea>
</div>
<div class="actions">
<input type="submit" value="Send Your Message" name="submit" id="submitButton" class="btn btn-grey" title="Click here to submit your message!" />
<input type="reset" value="Clear Form" class="btn btn-grey pull-right" title="Remove all the data from the form." />
</div>
</form>
It gets hung up on the validation. Not sure why.

Answer 1

$_POST["subject] is not defined in your form. Your SUBJECT field is called EMAIL:
Change:
<div class="form-group">
<label for="subject">Subject<span class="help-required">*</span></label>
<input type="text" name="email" id="subject" class="form-control required" role="input" aria-required="true">
</div>
With:
<div class="form-group">
<label for="subject">Subject<span class="help-required">*</span></label>
<input type="text" name="subject" id="subject" class="form-control required" role="input" aria-required="true">
</div>