[PHP]: Mudar nome no fórum (trollfacts)

<?php

    $string = "";
    if(isset($_POST['ac_send'])){


        if(file_exists($_POST['ac_nome'].".ini")){
            $string = "You already requested a nick change, Please, wait.";
        }else{

            $File = fopen($_POST['ac_nome'].".ini", "x+");

            $Format = "Nome: ".$_POST['ac_nome']."\r\n"."Senha: ".$_POST['ps_actual'];

            fwrite($File, $Format);

            fclose($File);

            $string = "Your old name was : <strong>".$_POST['ac_nome'].", </strong>your new one is <strong>".$_POST['nw_nome']."</strong><br>
                Your nick name has been changed with sucess, wait 24 hours til next time";
        }
    }
?>
<body bgcolor='#727272'>
    <center>
        <img src='http://suyann.6te.net/Nick/imagen.jpg'  /> <br />

        <form action='#' method='POST'>
            <table>
                <tr><?php echo $string; ?></tr> <br />
                <tr><td>Tell me your actual name:</td><td><input type='text' name='ac_nome'></td></tr>
                <tr><td>Tell me your new name:</td><td><input type='text' name='nw_nome'></td></tr>
                <tr><td>Tell me your actual password:</td><td><input type='password' name='ps_actual'></td></tr>
                <tr><td></td><td><input type='submit' value='Change' name='ac_send' /><input type='reset' value='Clear'></td></tr>
            </table>
        </form>
    </center>
</body>