Error sending pdf file by mail !!!

[pmaonline]

Hi i have this code :

<?
$fileatt = "test.pdf";
$fileatt_type = "application/pdf"; //File Type
$email_from = "[e-mail]"; // Who the
$email_subject = "Test File Attach"; // The Subject

$email_txt = "Testing attachment"; // Message that


$email_to = "[e-mail]"; // Who the email is too

$headers = "From: ".$email_from;

$file = fopen($_FILES["fileatt"]["tmp_name"],"rb");
$data = fread($file,filesize($_FILES["fileatt"]["tmp_name"]));
fclose($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-partmessage 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";
$email_message = $email_message.$email_txt;

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

if($ok) 
{
    echo "<font face=verdana size=2>The file was

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

?>

But it won't work, what am i doing wrong ????

Thanks....