[PHP] Why not working

[dean]

This should send me an e-mail with the form info then send a thank you
letter to the subscriber.
It does the first, but not second,  any ideas?
 
 
<?
$MailToAddress = "[EMAIL PROTECTED]";
$MailSubject = "Joine-mail list";
    if (!$MailFromAddress) {
    $MailFromAddress = "$email";
    }
$Header = "";
$Footer = "";
?>
                    <?
    if (!is_array($HTTP_POST_VARS))
    return;
reset($HTTP_POST_VARS);
    while(list($key, $val) = each($HTTP_POST_VARS)) {
    $GLOBALS[$key] = $val;
    $val=stripslashes($val);
   
    $Message .= "$key = $val\n";
    }
 
    if ($Header) {
    $Message = $Header."\n\n".$Message;
    }
 
    if ($Footer) {
    $Message .= "\n\n".$Footer;
    }
 
mail( "$MailToAddress", "$MailSubject", "$Message", "From:
$MailFromAddress");
?>    
 
 
 
                <?php
if(isset($Submit)) {
        $subject = "Thank You";
 $MailFromAddress = "[EMAIL PROTECTED]";
 
    while(list($key, $value) = each($HTTP_POST_VARS)) {
        $$key = $value;
        $msg .= "$key = $value\n";
    }
 
 
 
    $comment = "The thank you letter goes here";
 
// Send reply to them
   
mail( "$email", "$subject", "$comment", "From: $MailFromAddress");
    
}
?>