Hoe haal ik de verplichting van bijlage uit deze code?

<?php
     
                     
       $strname=ucfirst($_REQUEST["strname"]);
    $straddress=ucfirst($_REQUEST["straddress"]);
    $strcity=ucfirst($_REQUEST["strcity"]);
    $strstate=ucfirst($_REQUEST["strstate"]);       
       
       $phone=$_REQUEST["strno"];
       if($phone != ""){ $strno=$phone; } else { $strno="-"; }   
       
    $stremail=$_REQUEST["stremail"];   
    $strcomments=ucfirst($_REQUEST["strcomments"]);

   
    $filename=$_FILES["strresume"]["name"];
    $filetype=$_FILES["strresume"]["type"];
    $filesize=$_FILES["strresume"]["size"];
    $filetemp=$_FILES["strresume"]["tmp_name"];


       
    if($filetype=="application/octet-stream" or $filetype=="text/plain" or $filetype=="application/msword")
    {
   
        $message= '
   
   
            <table cellspacing="0" cellpadding="8" border="0" width="400">
            <tr>
                <td colspan="2"></td>
            </tr>
            <tr bgcolor="#eeeeee">
                <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;"><strong>Name</strong></td>
                <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;">'.$strname.'</td>
            </tr>
            <tr><td colspan="2" style="padding:0px;"><img src="images/whitespace.gif" alt="" width="100%" height="1" /></td></tr>
            <tr bgcolor="#eeeeee">
              <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;"><strong>Address</strong></td>
              <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;">'.$straddress.'</td>
              </tr>
            <tr><td colspan="2" style="padding:0px;"><img src="images/whitespace.gif" alt="" width="100%" height="1" /></td></tr>
            <tr bgcolor="#eeeeee">
              <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;"><strong>City</strong></td>
              <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;">'.$strcity.'</td>
              </tr>
              <tr><td colspan="2" style="padding:0px;"><img src="images/whitespace.gif" alt="" width="100%" height="1" /></td></tr>
            <tr bgcolor="#eeeeee">
              <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;"><strong>State</strong></td>
              <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;">'.$strstate.'</td>
              </tr>
              <tr><td colspan="2" style="padding:0px;"><img src="images/whitespace.gif" alt="" width="100%" height="1" /></td></tr>
            <tr bgcolor="#eeeeee">
              <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;"><strong>Contact No.</strong></td>
              <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;">'.$strno.'</td>
              </tr>
            <tr><td colspan="2" style="padding:0px;"><img src="images/whitespace.gif" alt="" width="100%" height="1" /></td></tr>
            <tr bgcolor="#eeeeee">
                <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;"><strong>Email</strong></td>
                <td style="font-family:Verdana, Arial; font-size:11px; color:#333333;">'.$stremail.'</td>
            </tr>
            <tr><td colspan="2" style="padding:0px;"><img src="images/whitespace.gif" alt="" width="100%" height="1" /></td></tr>
           
            <tr bgcolor="#eeeeee">
                <td colspan="2" style="font-family:Verdana, Arial; font-size:11px; color:#333333;"><strong>Comments</strong></td>
            </tr>               
            <tr bgcolor="#eeeeee">
                <td colspan="2" style="font-family:Verdana, Arial; font-size:11px; color:#333333;">'.$strcomments.'</td>
            </tr>               
                                   
            <tr><td colspan="2" style="padding:0px;"><img src="images/whitespace.gif" alt="" width="100%" height="1" /></td></tr>
         </table>


           

';

    // MAIL SUBJECT

    $subject = "Mail with doc file attachment";
   
    // TO MAIL ADDRESS
   
   
    $to="[email protected]";

/*
    // MAIL HEADERS
                       
    $headers  = "MIME-Version: 1.0\n";
    $headers .= "Content-type: text/html; charset=iso-8859-1\n";
    $headers .= "From: Name <[email protected]>\n";

*/
 


    // MAIL HEADERS with attachment

    $fp = fopen($strresume, "rb");
    $file = fread($fp, $strresume_size);

    $file = chunk_split(base64_encode($file));
    $num = md5(time());
   
        //Normal headers

    $headers  = "From: Name<[email protected]>\r\n";
       $headers  .= "MIME-Version: 1.0\r\n";
       $headers  .= "Content-Type: multipart/mixed; ";
       $headers  .= "boundary=".$num."\r\n";
       $headers  .= "--$num\r\n";

        // This two steps to help avoid spam   

    $headers .= "Message-ID: <".$now." TheSystem@".$_SERVER['SERVER_NAME'].">\r\n";
    $headers .= "X-Mailer: PHP v".phpversion()."\r\n";         

        // With message
       
    $headers .= "Content-Type: text/html; charset=iso-8859-1\r\n";
       $headers .= "Content-Transfer-Encoding: 8bit\r\n";
       $headers .= "".$message."\n";
       $headers .= "--".$num."\n"; 

        // Attachment headers

    $headers  .= "Content-Type:".$strresume_type." ";
       $headers  .= "name=\"".$strresume_name."\"r\n";
       $headers  .= "Content-Transfer-Encoding: base64\r\n";
       $headers  .= "Content-Disposition: attachment; ";
       $headers  .= "filename=\"".$strresume_name."\"\r\n\n";
       $headers  .= "".$file."\r\n";
       $headers  .= "--".$num."--";

   
   
    // SEND MAIL
       
       @mail($to, $subject, $message, $headers);
   

     fclose($fp);

    echo '<font style="font-family:Verdana, Arial; font-size:11px; color:#333333; font-weight:bold">Attachment has been sent Successfully.<br /></font>';
}
else
    {
        echo '<font style="font-family:Verdana, Arial; font-size:11px; color:#F3363F; font-weight:bold">Wrong file format. Mail was not sent.</font>';
        //echo "<script>window.location.href='careers.html';</script>";
    }

?>