ciao ragazzi sto facendo un piccolo form per mandare un email e al fondo devo mettere il controllo per il consenso x la privacy ma nn va... anche se nn metto il check manda comunque l'email.. come mai? dove sbaglio?

ecco il codice javascript:

Codice PHP:
    <script language="javascript">    
    
function 
conf() {
 
 if (
document.getElementById('conferma').checked) {
  
document.getElementById('invio').disabled false;
 }
 else
     
document.getElementById('invio').disabled true;
}

    
    
    function 
controlla()
    {
    
    
        if(
document.post.cognome.value == "" || document.post.cognome.value == null)
        {
            
alert(" è necessario inserire il Nome e il Cognome");
            return 
false;
        }
        if(
document.post.ditta.value == "" || document.post.ditta.value == null)
        {
            
alert(" è necessario inserire la ditta");
            return 
false;
        }

        if(
document.post.paese.value == "" || document.post.paese.value == null)
        {
            
alert(" è necessario inserire il Paese");
            return 
false;
        }
        if(
document.post.regione.value == "" || document.post.regione.value == null)
        {
            
alert(" è necessario inserire la Regione");
            return 
false;
        }
        if(
document.post.citta.value == "" || document.post.citta.value == null)
        {
            
alert(" è necessario inserire la Citta");
            return 
false;
        }
        if(
document.post.mail.value == "" || document.post.mail.value == null)
        {
            
alert(" è necessario inserire l'indirizzo e-mail");
            return 
false;
        }
        if(
document.post.telefono.value == "" || document.post.telefono.value == null)
        {
            
alert(" è necessario inserire il telefono");
            return 
false;
        }

        if(
document.post.mail.value.indexOf('@') == -|| document.post.mail.value.indexOf('.') == -1)
        {        
            
alert("indirizzo e-mail non valido");
            return 
false;
        }
        if(
document.post.note.value == "" || document.post.note.value == null)
        {
            
alert(" è necessario inserire il Messaggio");
            return 
false;
        }
        
        if(
document.post.consenso.value == "n" || document.post.consenso.value == null)
        {
            
alert(" è necessario selezionare ai sensi della legge.");
            return 
false;
        }

        
    }
    
    
    
</script> 
codice html

Codice PHP:
<form method="post" name="post" action="/img/fe/email_cliente.php?lingua=<?= $lang?>" onsubmit="return controlla()">
     
        <table style="padding-top:10px" width="100%" border="0" cellspacing="0" cellpadding="3" >
            
            <tr align="left">
                <td align="left" valign="top"> [b]<p style="font-size:15px">CONTATTACI[/b]</p>


 </td>
            </tr>
            
            <tr align="left">
                <td  align="left" valign="top">[b]Richiesta di *[/b]            </td>
                    
            </tr>            
            
            
            <tr align="left">
                <td align="left" valign="top"><select name="richiesta">
  <option selected="selected" value="informazioni">informazioni</option>
  <option value="richiesta_prodotti">richiesta prodotti</option>
  <option value="collabora">richiesta di collaborazione</option>
</select>
 </td>
            </tr>
            
            <tr align="left">
                <td  align="left" valign="top">[b]Nome e Cognome *[/b]            </td>
                    
            </tr>
            <tr>
            
            <td  ><input name="cognome" type="text" class="input" size="20"/>    </td>
            </tr>
            
            <tr align="left">
                <td align="left" valign="top">[b]Ditta *[/b]</td>
                
            </tr>
            <tr>
            <td><input name="ditta" type="text" class="input" size="20" />        </td>
            </tr>
            
            
            <tr align="left">
                <td align="left" valign="top">[b]Regione *[/b]</td>
                
            </tr>
            <tr>
            <td><input name="regione" type="text" class="input" size="20" />        </td>
            </tr>

            <tr >
                <td align="left" valign="top">[b]Citta *[/b]</td>
                
            </tr>

            <tr>
            <td><input name="citta" type="text" class="input" size="20" />        </td>
            </tr>
         
                            
                            
                             <tr >
                                <td align="left" valign="top">[b]E-mail *[/b]                    </td>
                                    
                              </tr>
                            <tr>
                            
                            <td><input name="mail" type="text" class="input" size="20"/>                    </td>
                            </tr>
                    
                        <tr>
                    <tr align="left">
                        <td align="left" valign="top" >[b]Telefono *[/b]                        </td>
                        
                    </tr>
                    
                    <tr>
                    
                    <td ><input name="telefono" type="text" class="input" size="20"/>                </td>
                    </tr>
                    
                    <tr align="left">
                        <td align="left" valign="top" >[b]Prodotti di interesse[/b]                        </td>
                        
                    </tr>
                    <tr>
                    
                    <td><input name="prodotti" type="text" class="input" size="20"/>                </td>
                    </tr>
                    
                    <tr align="left">
                <td align="left" valign="top">[b]Messaggio: *[/b]            </td>
                
    
        </tr>
        <tr>
        <td align="left" valign="top"> <textarea name="note" cols="18" rows="6" class="textarea"></textarea>

    </td>
        </tr>

                    <tr>
                        
                        <td class="nota" align="left"> Premere "invia" per generare un' email alla sede centrale di APE Group.


</td>
                    </tr>                    
                    
                    
                    <tr>
                    <td class="nota" valign="middle" align="left"><input type="checkbox" id="conferma" onclick="conf()" \> accetta ai sensi della legge


</td>
                    
                    
                    
                    </tr>

                    
                    <tr>
                    <td class="nota" align="left">* Campi obbligatori</td>
                    
                    
                    
                    </tr>
                    <tr>
                        <td ><div align="left">

                            <input type="submit" name="Inserisci" id="invio" value="Invia" class="bottone" />
                            <input type="reset" name="reset_campi" value="Reimposta" class="bottone" />
                        </div></td>
                    </tr>
                    
                    
                    </table>
      </form>