Hilfe!!! php class läuft nicht

[marcus]

hallo leute,
ich möchte mit der untenstehenden script eine email mit anhang
verschicken, aber es kommen nur fehlermeldungen, wäre echt super wenn sich das jemand von euch mal anschauen könnte.

thx.

<?php
$betreff = "ad Award";
$inhalt =  "Contact Person: $mpc_c_p\n
   Category: $ca\n
   Original Title: $ot\n";

class mime_mail
 {
 var $parts;
 var $to;
 var $from;
 var $headers;
 var $subject;
 var $body;

/*
  *     void mime_mail()
  *     class constructor
  */
 function mime_mail()
  {
  $this->parts = array();
  $this->to =  "";
  $this->from =  "";
  $this->subject =  "";
  $this->body =  "";
  $this->headers =  "";
  }

/*
  *     void add_attachment(string message, [string name], [string ctype])
  *     Add an attachment to the mail object
  */
 function add_attachment($message, $name =  "", $ctype =  "application/octet-stream")
  {
  $this->parts[] = array (
                           "ctype" => $ctype,
                           "message" => $message,
                           "encode" => $encode,
                           "name" => $name
                          );
  }

/*
 *      void build_message(array part=
 *      Build message parts of an multipart mail
 */
function build_message($part)
 {
 $message = $part[ "message"];
 $message = chunk_split(base64_encode($message));
 $encoding =  "base64";
 return  "Content-Type: ".$part[ "ctype"].
                        ($part[ "name"]? "; name = "".$part[ "name"]. """ :  "").
                         "\nContent-Transfer-Encoding: $encoding\n\n$message\n";
 }

/*
 *      void build_multipart()
 *      Build a multipart mail
 */
function build_multipart()
 {
 $boundary =  "b".md5(uniqid(time()));
 $multipart =  "Content-Type: multipart/mixed; boundary = $boundary\n\nThis is a MIME encoded message.\n\n--$boundary";

for($i = sizeof($this->parts)-1; $i >= 0; $i--)
    {
    $multipart .=  "\n".$this->build_message($this->parts[$i]). "--$boundary";
    }
 return $multipart.=  "--\n";
 }

/*
 *      void send()
 *      Send the mail (last class-function to be called)
 */
function send()
 {
 $mime =  "";
 if (!empty($this->from))
    $mime .=  "From: ".$this->from. "\n";
 if (!empty($this->headers))
    $mime .= $this->headers. "\n";

if (!empty($this->body))
    $this->add_attachment($this->body,  "",  "text/plain");
 $mime .=  "MIME-Version: 1.0\n".$this->build_multipart();
 mail($this->to, $this->subject,  "", $mime);
 }
};  // end of class

$attachment = fread(fopen($filename, "r"), $filename_size);

$mail = new mime_mail();
 $mail->from = "[e-mail]";
 $mail->headers = "Location: smart_ad_award.php";
 $mail->to = "[e-mail]";
 $mail->subject = "Smart ad Award";
 $mail->body = "$inhalt";
 $mail->$mail->add_attachment($attachment, $filename_name, $filename_type);
 $mail->send();

?>