I have a form on this page - http://www.organicspirit.co.uk/contact.php using the script called "send_contact.php" when submitted.

It used to work but now when you hit submit, you get following message -
500 - Internal server error.
There is a problem with the resource you are looking for, and it cannot be displayed.

Do I need to understand that the issue lies with the hosting provider or is there something wrong with my script (which I pasted below)

send_contact.php ---------------------------------------

// Contact subject
$subject = $_POST['subject'];
// Details
$message = $_POST['detail'];
// Mail of sender
$mail_from = $_POST['customer_mail'];
// From
$header = "from: $name <$mail_from>";
// Enter your email address
$to = 'info@organicspirit.co.uk';
$send_contact = mail($to,$subject,$message,$header);
// Check, if message sent to your email

header ('Location: http://www.organicspirit.co.uk/thank-you.html');
exit ();

echo "We've received your contact information";
else {
echo "ERROR";

Thank you for your help!