form contattaci problema

[mybox]

<?php
header("Content-type: text/vnd.wap.wml; charset=ISO-8859-1");
echo"<?xml version=\"1.0\"?>"; ?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN"
            "http://www.wapforum.org/DTD/wml_1.1.xml">
<?
$TimeZone="12.49"; 
$time = time() + ($TimeZone * 60 * 60)
?>
<wml>            
<?
$wap_title="Site"; 
$to = "xxx@xxx.com"; 
$time = "".date("D,d-F-Y g:i a", $time)."";
if ($pass == "")
{
    $title="Registrati a $wap_title";
    }
else 
{    
    $title="Grazie!";
    $msg .= "Nome: $nome\n\nEmail: $email\n\nFirma: $signature\n\nNato: $nascita\n\nSesso: $sex\n\nNick: $nick\n\nBrowser: $HTTP_USER_AGENT\n\n Ip: $REMOTE_ADDR\n\nOrario: $time ";
    $subject = "Registrazione forum\n";
    $mailheaders = "Da: $nome<$email> \n";
    $mailheaders .= "Rispondere a: $nome<$email>\n\n";
    mail($to, $subject, $msg, $mailheaders);    
    print("<card id=\"thanks\" title= \"$title\" >");
    print("<p align=\"center\">[size="1"]Grazie $nome,
Risponderemo il prima possibile.[/size]</p>");
        print (" <p align=\"center\">[size="1"]<a href=\"index.php\">Home</a>[/size]</p>");
    print("</card>"); 
}      
?>
<card id="contact" title="Registrazione">
<p align="center">[size="1"]contattaci compilando [b]TUTTI[/b] i campi e inserendo una email [b]VALIDA[/b] altrimenti non riceverete mai la risposta !!!


[b]Nome:[/b]
 
<input title="nome" name="nome"/>

[b]Email:[/b]

<input title="email" name="email"/>

[b]Nato/a il:[/b]
 
<input title="nascita" name="nascita"/>

[b]Sesso:[/b]
 
<input title="sex" name="sex"/>

[b]Nick:[/b]

<input title="nick" name="nick"/>

[b]Firma:[/b]

<input title="signature" name="signature"/>

<anchor>Invia
<go method="post" href="<? echo "$PHP_SELF"; ?>">
<postfield name="nome" value="$nome"/>
<postfield name="email" value="$email"/>
<postfield name="nascita" value="$nascita"/>
<postfield name="sex" value="$sex"/>
<postfield name="nick" value="$nick"/>
<postfield name="signature" value="$signature"/>
<postfield name="pass" value="1"/>
</go></anchor>
<b/>
[url="index.php"]Home[/url]
[b]Copy[/b]
[/size]
</p>
</card>
</wml>

qualcosa non va...quando faccio invio mi aggiorna la pagina del contattaci nuovamente ma la mail non parte...come posso risolvere??? help