send email with attachment

<?php
$fileatt = "mypdffile.pdf"; // Path to the file
$fileatt_type = "application/pdf"; // File Type
$fileatt_name = "mypdffile.pdf"; // Filename that will be used for the file as the attachment

$email_from = "sales@mysite.com"; // Who the email is from 
$email_subject = "Your attached file"; // The Subject of the email
$email_message = "Thanks for visiting mysite.com! Here is your free file.
";
$email_message .= "Thanks for visiting.
"; // Message that the email has in it

$email_to = $_POST['email']; // Who the email is to

$headers = "From: ".$email_from;

$file = fopen($fileatt,'rb'); 
$data = fread($file,filesize($fileatt));
fclose($file);

$semi_rand = md5(time()); 
$mime_boundary = "==Multipart_Boundary_x{$semi_rand}x";

$headers .= "\nMIME-Version: 1.0\n" .
"Content-Type: multipart/mixed;\n" .
" boundary=\"{$mime_boundary}\"";

$email_message .= "This is a multi-part message in MIME format.\n\n" . 
"--{$mime_boundary}\n" .
"Content-Type:text/html; charset=\"iso-8859-1\"\n" .
"Content-Transfer-Encoding: 7bit\n\n" .
$email_message .= "\n\n";

$data = chunk_split(base64_encode($data));

$email_message .= "--{$mime_boundary}\n" . 
"Content-Type: {$fileatt_type};\n" .
" name=\"{$fileatt_name}\"\n" .
//"Content-Disposition: attachment;\n" .
//" filename=\"{$fileatt_name}\"\n" .
"Content-Transfer-Encoding: base64\n\n" .
$data .= "\n\n" .
"--{$mime_boundary}--\n";

$ok = @mail($email_to, $email_subject, $email_message, $headers);

if($ok) { 
echo "You file has been sent
to the email address you specified.

Make sure to check your junk mail!

Click here to return to mysite.com.";

} else { 
die("Sorry but the email could not be sent. Please go back and try again!");
}
?>