Hi, I am new to using PHP (in fact its my very first time) and I have to finish a contact form for class. We have to make a form that includes name, email, birthday, and a message box. When it submits, the information has to be sent to both me and the user, and the page displays a thank you message.

Here is what I have so far:
<form method="post" action="contact.php"> 
Name: <input name="name" type="text"><br>
Birthday: <input name="birthday" type="text"><br>
 Email: <input name="email" type="text"><br>
 <textarea name="message" rows="15" cols="40"></textarea><br> 
 <input type="submit"> 
 $to = "myemail@provider.com"; 
 $subject = "Contact Us"; 
$birthday = $_REQUEST ['birthday'] ;
$name = $_REQUEST['name'] ;
 $email = $_REQUEST['email'] ; 
 $message = $_REQUEST['message'] ; 
 $headers = "From: $email"; 
 $sent = mail($to, $subject, $message, $headers) ; 
 {print "Your mail was sent successfully"; }
 {print "We encountered an error sending your mail"; }
I am wondering how to get the code to also email to the recipient, myself, and display the thank you message at the end. Every time I hit submit I get a 404 error. What am I doing wrong and how can I fix this?