Ho scritto questo form e questo è il codice.

Codice PHP:
<?php
    
// funziona che controlla il formato della mail inserita dall'utente
    
function is_email($email)
    {
        
$pattern '/[\w\-]+(\.[\w\-]+)*@[\w\-]+(\.[\w\-]+)+/';
        return 
preg_match($pattern$email);
    }
    if (isset(
$_POST['invia']))
    {
        
// prima di proseguire si assicura che il form sia stato compilato da un umano
        
if ($_POST['umano'] == '')
        {
            
// pulisce i valori inseriti dall'utente
            
$nome trim($_POST['nome']);
            
$email trim($_POST['email']);
            
$messaggio trim($_POST['messaggio']);
            
// controllo dei dati inseriti dall'utente
            
$errore '';
            if (
strlen($nome) < 2)
            {
                
$errore '

Nome troppo corto. Usa almeno due caratteri</p>'
;
            }
            if (!
is_email($email))
            {
                
$errore .= '

Email non valida.</p>'
;
            }
            if (
strlen($messaggio) < 10)
            {
                
$errore .= '

Messaggio non valido. Usa almeno 10 caratteri.</p>'
;
            }
            if (
$errore == '')
            {
                include(
'phpmailer/class.phpmailer.php');
                
$a_me = new PHPMailer();
                
$a_me->From $email;
                
$a_me->FromName $nome;
                
$a_me->AddAddress('qui ho messo il mio indirizzo email');
                
$a_me->AddReplyTo($email);
                
$a_me->Subject $_POST['richiesta'];
                
$a_me->Body $messaggio;
                if (
$a_me->Send())
                {
                    
$id 'inviato';
                }
                else
                {
                    
$id 'non_inviato';
                    
$errore "

Errore durante l'invio del messaggio.</p>"
;
                }
            }
            else
            {
                
$id 'non_inviato';
            }
        }
    }
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="it" xml:lang="it">
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
        <title>Egidio Web Designer | Contattami</title>
        <link rel="stylesheet" type="text/css" media="all" href="css/stile.css" />
        <style type="text/css">
            table
            {
                font-family: 'AllerRegular';
                color: #4c4c4c;
                font-size: 14px;
                line-height: 22px;
                border-collapse:separate;
                border-spacing:5px 10px;
            }
            textarea, input
            {
                font-family: 'AllerLightRegular';
                color: #000;
                font-size: 13px;
                line-height: 21px;
            }
            td
            {
                vertical-align: top;
            }
<?php
    
if (isset($_POST['invia']))
    {
        echo 
'
            #inviato
            {
                padding: 20px;
                border: 3px solid #00cc00;
            }
            #non_inviato
            {
                padding: 20px;
                border: 3px solid #cc0000;
            }
            #inviato p
            {
                color: #00cc00;
            }
            #non_inviato p
            {
                color: #cc0000;
            }
'
;
    }
?>
        </style>
    </head>
    <body>
        
<?php
    
include('intestazione.php');
?>
        
        
        <div id="contenitore">
            
            <div id="corpo">
                <div id="<?php echo $id?>">
<?php
    
if (isset($_POST['invia']))
    {
        if (
$errore != '')
        {
            echo 
$errore;
        }
        else
        {
            echo 
'

Messaggio inviato correttamente!</p>

Grazie per avermi contattato.</p>

Ti risponder&ograve; appena possibile.</p>'
;
        }
    }
?>
                </div>
                <h1 
<?php
    
if (isset($_POST['invia']))
    {
        echo 
'style="margin-top: 50px;"';
    }
?>
                >Contattami</h1>
                <form action="contattami.php" method="post">
                    <table>
                        <tr>
                            <td>

Nome</p></td>
                            <td>
                                <input type="text" name="nome" />
                            </td>
                        </tr>
                        <tr>
                            <td>

Email</p></td>
                            <td>
                                <input type="text" name="email" />
                            </td>
                        </tr>
                        <tr>
                            <td>

Richiesta</p></td>
                            <td>
                                <select name="richiesta">
                                    <option value="sito">Creazione sito web</option>
                                    <option value="aiuto">Richiesta di aiuto generale</option>
                                    <option value="commento">Commento all'autore</option>
                                    <option value="altro">Altro</option>
                                </select>
                            </td>
                        </tr>
                        <tr>
                            <td>

Messaggio</p></td>
                            <td>
                                <textarea rows="5" cols="50" name="messaggio"></textarea>
                            </td>
                        </tr>
                        <tr>
                            <td></td>
                            <td style="text-align: center;">
                                <input type="reset" name="cancella" value="Cancella" />
                                <input type="submit" name="invia" value="Invia" />
                                

                                <input type="input" name="umano" style="opacity: 0;" />
                            </td>
                        </tr>
                    </table>
                </form>
            </div>
            
            
            <div id="barra_laterale">
                
<?php
    
include('pubblicita.php');
?>
                
            </div>
            
            
<?php
    
include('pie_di_pagina.php');
?>
            
        </div>
        
    </body>
</html>
Compilando tutti i campi, l'email non mi viene inviata, eppure non visualizzo nessun messaggio d'errore.

Come è possibile?