Re direct to a thank you page after submit button pressed Options

[Ted]

This is my first post and I have little experience with php scripts so I have created a web site with a form for a customer to enter their details. All works and I get an email with their details. The customer gets a plain page with a Thank you message. I want to change that to my custom thankyou.html page but with no success. I get this error on a plain page - Warning: Cannot modify header information - headers already sent by (output started at /var/sites/r/ringsjustforyou.co.uk/public_html/html_form_send.php:1) in /var/sites/r/ringsjustforyou.co.uk/public_html/html_form_send.php on line 80.
This is my html code for the form;-
<!-- Start of the form Code -->
<div id="sendform">
<form name="htmlform" method="post" action="html_form_send.php"><table width="450px">
<tr>
<td valign="middle"><label for="first_name">First Name *</label></td>
<td valign="top"><input type="text" name="first_name" maxlength="50" size="30" /></td>
</tr>
<tr>
<td valign="middle"><label for="last_name">Last Name *</label></td>
<td valign="top"><input type="text" name="last_name" maxlength="50" size="30" /></td>
</tr>
<tr>
<td valign="middle"><label for="email">Email Address *</label></td>
<td valign="top"><input type="text" name="email" maxlength="80" size="30" /></td>
</tr>
<tr>
<td valign="middle"><label for="telephone">Telephone Number</label></td>
<td valign="top"><input type="text" name="telephone" maxlength="30" size="30" /></td>
</tr>
<tr>
<td valign="top"><label for="comments">Enquires *</label></td>
<td valign="top"><textarea name="comments" maxlength="1000" cols="25" rows="10"></textarea></td>
</tr>
<tr>
<td colspan="2" style="text-align:center"><input type="submit" value="Submit" /><a href= "http://www.ringsjustforyou.co.uk/html_form.php"></a></td>
</tr>
</table>
</form>
</div>
<!-- End of the Form code -->

This is the code for the php file html_form_send.php;-
<?php
if(isset($_POST['email'])) {

// CHANGE THE TWO LINES BELOW
$email_to = "*@ringsjustforyou.co.uk";

$email_subject = "Custom Ring(s) Request";


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($_POST['first_name']) ||
!isset($_POST['last_name']) ||
!isset($_POST['email']) ||
!isset($_POST['telephone']) ||
!isset($_POST['comments'])) {
died('We are sorry, but there appears to be a problem with the form you submitted.');
}

$first_name = $_POST['first_name']; // required
$last_name = $_POST['last_name']; // required
$email_from = $_POST['email']; // required
$telephone = $_POST['telephone']; // 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($email_exp,$email_from)) {
$error_message .= 'The Email Address you entered does not appear to be valid.<br />';
}
$string_exp = "/^[A-Za-z .'-]+$/";
if(!preg_match($string_exp,$first_name)) {
$error_message .= 'The First Name you entered does not appear to be valid.<br />';
}
if(!preg_match($string_exp,$last_name)) {
$error_message .= 'The Last Name you entered does not appear to be valid.<br />';
}
if(strlen($comments) < 2) {
$error_message .= 'The Comments you entered do not appear to be valid.<br />';
}
if(strlen($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);
}

$email_message .= "First Name: ".clean_string($first_name)."\n";
$email_message .= "Last Name: ".clean_string($last_name)."\n";
$email_message .= "Email: ".clean_string($email_from)."\n";
$email_message .= "Telephone: ".clean_string($telephone)."\n";
$email_message .= "Comments: ".clean_string($comments)."\n";


// create email headers
$headers = 'From: '.$email_from."\r\n".
'Reply-To: '.$email_from."\r\n" .
'X-Mailer: PHP/' . phpversion();
@mail($email_to, $email_subject, $email_message, $headers);
?>

<!-- place your own success html below

Thank you for your enquiry. We will be in touch with you very soon. -->


<?php

header("Location: ./http://www.ringsjustforyou.co.uk/thankyou.php");

}
die();
?>

The line 80 in the error massage refers to this;-
Header ("Location: ./http://www.ringsjustforyou.co.uk/thankyou.php");
I have tried the thankyou page as .html and .php with the same error
I hope I have told you enough to help me

Thank you in advance

This post has been edited by Christian J: Sep 7 2018, 10:46 AM