help with PHP/Sendmail code

Hey out there!

I am trying to get a simple PHP/Sendmail form working and I must admit I am still just learning. Can anyone help?

Here is the code on my HTML page:

<form enctype="multipart/form-data" action="submit.php" method="post">
<p class="text">Name: <input type='text' name='name' size='40' value=''><br>
Email Address: <input type='text' name='email' size='40' value=''><br>
Attachment:<input size=45 type="file" name='message' /><br>
<input type="submit" name="submit" value=" Submit "></form>

and here is the PHP file it is referencing in the same directory:

<?
$name = $_REQUEST['name'] ;
$email = $_REQUEST['email'] ;
$message = $_REQUEST['message'] ;

mail( "me@someisp.com", "Feedback Form Results",
$message, "From: $email" );
header( "Location: ty.html" );
?>

I am getting the thank you page to load but I am not getting any content or attachment. Do I need to specify the file type or size?

Please help!

Knotthead