private void Regisztracio(){
        String uname, pass, mail;
            System.out.println("Please enter your datas");
            System.out.print("Username: ");
            try{
                do{
                    uname = keyboardInput();
                }while(!adatbazis.felhasznalonevEllenorzese(uname, "felhasznaloiadatbazis.txt"));
                System.out.print("E-mail: ");
                do{
                    mail = keyboardInput();
                }while(!adatbazis.emailEllenorzese(mail));
                System.out.print("Jelszo: ");
                do{
                    pass = keyboardInput();
                }while(!adatbazis.jelszoEllenorzese(pass));
                Szemelyek ujSzemely = new Vasarlo(uname, mail, pass);
                adatbazisbaMentes("felhasznaloiadatbazis.txt", ujSzemely);
            }
            catch(IOException e)
            {
                System.out.println("Hiba tortent!");
            }
    }