private void jButtonRegisterActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButtonRegisterActionPerformed
        // TODO add your handling code here:
        String firstName = jTextFirstName.getText();
        String lastName = jTextLastName.getText();
        String username = jTextUsername.getText();
        String password = new String(jPassword.getPassword());
        try{
            BufferedReader reader = new BufferedReader(new FileReader("/Users/pantvad/Downloads/Security_Project3/src/main/java/users.txt"));
            boolean check = false;
            for(String line;(line = reader.readLine()) != null;) {
                int i = line.indexOf('-');
                String testString = line.substring(0, i);
                if (testString.equals(username)) {
                    check = true;
                    break;
                }
            }
            if(!check) {
                StringBuilder usersInfo = new StringBuilder(username);
                usersInfo.append("-");
                usersInfo.append(firstName);
                usersInfo.append("-");
                usersInfo.append(lastName);
                usersInfo.append("-");
                usersInfo.append(password.hashCode());
                String last = usersInfo.toString();
                System.out.println(last);
                PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("/Users/pantvad/Downloads/Security_Project3/src/main/java/users.txt", true)));
                out.println(last);
                out.close();

                JOptionPane.showMessageDialog(new JFrame(), "Register Successfull");
            }
            else{
                JOptionPane.showMessageDialog(new JFrame(), "Username already exists");
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        //System.out.println(firstName + lastName + username + password);
    }