Sending mail with attachment using php

HTML Design:

<form id="attach" name="attach" method="post" action="attach.php" enctype="multipart/form-data">

     <table>
         <tr>
              <td>To</td><td>:</td><td><input type="text" name="to" id="to"></td>
         </tr>
         <tr>
              <td>Subject</td><td>:</td><td><input type="text" name="subject" id="subject"></td>
         </tr>
         <tr>
              <td>Message</td><td>:</td><td><input type="text" name="msg" id="msg"></td>
          </tr>
          <tr>
              <td>Attachment<span class="imp">*</span></td><td>:</td><td><input type="file" name="upload" id="upload"></td>
          </tr>
          <tr>
              <td></td><td></td><td><input type="submit" value="Submit" id="send" name="send"></td>
          </tr>
    </table>
</form>

PHP Script File (attach.php):

<?php


 if(isset ($_POST["send"]))
 {
    $upload_name=$_FILES["upload"]["name"];
    $upload_type=$_FILES["upload"]["type"];
    $upload_size=$_FILES["upload"]["size"];
    $upload_temp=$_FILES["upload"]["tmp_name"];
    $message=$_POST["msg"];
    $subject = $_POST["subject"];
    $to=$_POST["to"];


    if($message==""||$subject==""||$to=="")
    {
        echo '<font style="font-family:Verdana, Arial; font-size:11px; color:#F3363F; font-weight:bold">Please fill all fields</font>';
    }
    else
    {
        $fp = fopen($upload_temp, "rb");
    $file = fread($fp, $upload_size);

    $file = chunk_split(base64_encode($file));
    $num = md5(time());

        //Normal headers

    $headers  = "From: Info Mail<serma2089@gmail.com>\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

    $headers .= "Message-ID: <".gettimeofday()." TheSystem@".$_SERVER['http://www.webizyme.com'].">\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

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

    // SEND MAIL

       $check = mail($to, $subject, $message, $headers);
       echo $check;

     fclose($fp);
     if($check){
    echo '<font style="font-family:Verdana, Arial; font-size:11px; color:#333333; font-weight:bold">Mail sent please check inbox and spam both <br /></font>';
}
 }
 }
?>

I hope this will be helpful for all web developers.

Thank You