Frage zum Php scribt

<?php
/* PHP Form Mailer - phpFormMailer v2.1, last updated 30th Nov 2005 - check back often for updates!
   (easy to use and more secure than many cgi form mailers) FREE from:
                  [url]www.TheDemoSite.co.uk[/url]
      Should work fine on most Unix/Linux platforms */


// ------- three variables you MUST change below  -------------------------------------------------------
$valid_ref1="http://www.XXXXXXXXX/contact.html";// chamge "Your--domain" to your domain
$valid_ref2="http://www.XXXXX/contact.html";// chamge "Your--domain" to your domain
$replyemail="info@XXXXXXX.de";//change to your email address
// ------------------------------------------------------------


//clean input in case of header injection attempts!
function clean_input_4email($value, $check_all_patterns = true)
{
 $patterns[0] = '/content-type:/';
 $patterns[1] = '/to:/';
 $patterns[2] = '/cc:/';
 $patterns[3] = '/bcc:/';
 if ($check_all_patterns)
 {
  $patterns[4] = '/\r/';
  $patterns[5] = '/\n/';
  $patterns[6] = '/%0a/';
  $patterns[7] = '/%0d/';
 }
 //NOTE: can use str_ireplace as this is case insensitive but only available on PHP version 5.0.
 return preg_replace($patterns, "", strtolower($value));
}


$name = clean_input_4email($_POST["name"]);
$email = clean_input_4email($_POST["email"]);
$thesubject = clean_input_4email($_POST["thesubject"]);
$themessage = clean_input_4email($_POST["themessage"], false);


$error_msg='ERROR - not sent. Try again.';


$success_sent_msg='<p align="center">[b][/b]</p>
                   <p align="center">[b]Your message has been successfully sent to us


                   [/b] and we will reply as soon as possible.</p>
                   <p align="center">A copy of your query has been sent to you.</p>
                   <p align="center">Thank you for contacting us.</p>';


$replymessage = "Hi $name


Thank you for your email.


We will endeavour to reply to you shortly.


Please DO NOT reply to this email.


Below is a copy of the message you submitted:
--------------------------------------------------
Subject: $thesubject
Query:
$themessage
--------------------------------------------------


Thank you";


// email variable not set - load $valid_ref1 page
if (!isset($_POST['email']))
{
 echo "<script language=\"JavaScript\"><!--\n ";
 echo "top.location.href = \"$valid_ref1\"; \n// --></script>";
 exit;
}


$ref_page=$_SERVER["HTTP_REFERER"];
$valid_referrer=0;
if($ref_page==$valid_ref1) $valid_referrer=1;
elseif($ref_page==$valid_ref2) $valid_referrer=1;
if(!$valid_referrer)
{
 echo "<script language=\"JavaScript\"><!--\n alert(\"$error_msg\");\n";
 echo "top.location.href = \"$valid_ref1\"; \n// --></script>";
 exit;
}
$themessage = "name: $name \nQuery: $themessage";
mail("$replyemail",
     "$thesubject",
     "$themessage",
     "From: $email\nReply-To: $email");
mail("$email",
     "Receipt: $thesubject",
     "$replymessage",
     "From: $replyemail\nReply-To: $replyemail");
echo $success_sent_msg;
/*
  PHP Form Mailer - phpFormMailer (easy to use and more secure than many cgi form mailers)
   FREE from:


    [url]www.TheDemoSite.co.uk[/url]       */
?>

<form name="phpformmailer" action="contact.php" align="center" method="post">
  <div align="center"><center><table bgcolor="#F2F2F2" width="528" cellspacing="6">
    <tr>
      <td width="159">[b]Contact Us[/b]</td>
      <td width="349"></td>
    </tr>
    <tr>
      <td align="right" width="159">[size=8]Your name:[/size]</td>
      <td width="349"><font face="Arial"><input class="inputc" size="29" name="name"></font></td>
    </tr>
    <tr>
      <td align="right" width="159"><font color="#000080" size="1">*</font>[size=8] Your email
      address:[/size]</td>
      <td align="left" width="349"><font face="Arial"><input class="inputc" size="29"
      name="email"></font></td>
    </tr>
    <tr align="middle">
      <td align="right" width="159"><font color="#000080" size="1">*</font>[size=8] Confirm email
      address:[/size]</td>
      <td width="349" align="left"><font face="Arial"><input class="inputc" size="29"
      name="email2"></font></td>
    </tr>
    <tr>
      <td align="right" width="159"><font color="#000080" size="1">*</font>[size=8] Subject:[/size]</td>
      <td width="349"><font face="Arial"><input class="inputc" size="29" name="thesubject"></font></td>
    </tr>
    <tr>
      <td align="right" width="159">


<font color="#000080" size="1">*</font>[size=8] Your
      request or query:[/size]</td>
      <td width="349"><textarea style="FONT-SIZE: 10pt" name="themessage" rows="7" cols="27"></textarea></td>
    </tr>
    <tr>
      <td width="159"></td>
      <td width="349"><script language="JavaScript"><!--
function validateForm() 
{
 var okSoFar=true
 with (document.phpformmailer)
 {
  var foundAt = email.value.indexOf("@",0)
  if (foundAt < 1 && okSoFar)
  {
    okSoFar = false
    alert ("Please enter a valid email address.")
    email.focus()
  }
  var e1 = email.value
  var e2 = email2.value
  if (!(e1==e2) && okSoFar)
  {
    okSoFar = false
    alert ("Email addresses you entered do not match.  Please re-enter.")
    email.focus()
  }
  if (thesubject.value=="" && okSoFar)
  {
    okSoFar=false
    alert("Please enter the subject.")
    thesubject.focus()
  }
  if (themessage.value=="" && okSoFar)
  {
    okSoFar=false
    alert("Please enter the details for your enquiry.")
    themessage.focus()
  }
  if (okSoFar==true)  submit();
 }
}
// --></script><input type="button" class="button"
      value="Send" name="B1" ONCLICK="javascript:validateForm()">[size=8] <small>You must fill in
      the fields marked with a *[/size]</small></td>
    </tr>
  </table>
  </center></div>
</form>