$this->c=@mysql_query("select username from users where username='$susername'");

Fatal error:  Using $this when not in object context in /home/fotozrzut/domains/fotozrzut.pl/public_html/rejestracja.php on line 38

    } else if($submit3) {
        if(!ereg("^[A-Za-z0-9_]{1,16}$",$susername)) {
            $serror="Błędna nazwa! Możesz użyć malsymalnie 15 znaków. Możesz używać liter, cyfer i kropek.<br>";
        }
        $this->c=@mysql_query("select username from users where username='$susername'");
        $this->d=mysql_fetch_object($this->c);
        if(is_object($this->d)) { $serror="Podany login jest już zajęty.<br>"; }
        $this->c=@mysql_query("select username from users where username='$susername'");
        $this->d=mysql_fetch_object($this->c);
        if(is_object($this->d)) { $serror="Podany login jest już zajęty.<br>"; }
        if (!$serror) {
            mt_srand((double)microtime()*1000000^getmypid());
            $pass_length = mt_rand($this->min_pass_length,$this->max_pass_length);
            while(strlen($spassword)<$pass_length) {
                $spassword.=substr($this->chars,(mt_rand()%strlen($this->chars)),1);
            }
            include("include/email.php");
            $signupmessage=str_replace("<username>","$susername",$signupmessage);
            $signupmessage=str_replace("<password>","$spass",$signupmessage);
            $signupmessage=str_replace("<bupass>","$bupass",$signupmessage);
            $adminsignupmessage = str_replace("<member_email>","$semail",$adminsignupmessage);
            $subject = "$signupsubject";
            $message = "$signupmessage";
            mail($semail,$subject,$message,"From: $adminemail");
                        $adminsignupsubject=str_replace("<username>","$susername",$adminsignupsubject);
            $adminsignupmessage = str_replace("<username>","$susername",$adminsignupmessage);
            $adminsignupmessage = str_replace("<password>","$spass",$adminsignupmessage);
            $adminsignupmessage = str_replace("<bupass>","$bupass",$adminsignupmessage);
            $adminsignupmessage = str_replace("<member_email>","$semail",$adminsignupmessage);
            $subject = "$adminsignupsubject";
            $message = "$adminsignupmessage";
            mail($adminemail,$subject,$message,"From: $adminemail");
            $nowdate = date("M d, Y");

            mysql_query("insert into users (uid, username, password, email, last_paid, signup_date) values ('','$susername', '$spass', '$semail', 'free', '$nowdate')");
            echo "<h3>Zakładanie nowego konta Krok 3 - Zakończone</h3> $table2
            <tr><td align=center>Dziękujemy za doł±czenie do grona użytkowników $sitename. Na podany przez Ciebie email (<b>$semail</b>) została wysłana wiadomo¶ć z danymi konta. </table>";
}