public int nameAvailable(MyUserApp app, String name) throws SQLException{
    String sql = "SELECT * FROM user n WHERE username = '"+ name +"';";
    Statement st = app.getCon().createStatement();
    ResultSet rs =  st.executeQuery(sql);
    int numResults = rs.getFetchSize();

    return numResults;
}

private void RegisterButtonActionPerformed(java.awt.event.ActionEvent evt) {
    String username, password, address, dob;
    boolean status;
    String u;
    try {

        username = newUsernameField.getText();
        password = passwordField2.getText();
        address = addressField.getText();
        dob = dateofbField.getText();
        int no= 5;

        if( username.isEmpty() || password.isEmpty() || password.length() < 6 ){
            jLabel6.setText("The information you typed in is not valid. ");
            status = false;
            showTableDB.setText(""+status);
        }
        else{
                no = this.app.nameAvailable(app, username);
                jLabel6.setText(no+"");
                if(no == 0){
                    jLabel6.setText("Registered your account, "+username+"!" + no);
                    status = this.app.registerUser(app, username, password, dob, address);
                    u = this.app.showInfo(app, username);
                    showTableDB.setText(u);
                    no = this.app.nameAvailable(app, username);
                }
                else{
                    showTableDB.setText("That username is token. Please choose a different one.");
                }


                }


    } catch (SQLException ex) {
        Logger.getLogger(UserAppUI.class.getName()).log(Level.SEVERE, null, ex);
    } catch (InterruptedException ex) {
        Logger.getLogger(UserAppUI.class.getName()).log(Level.SEVERE, null, ex);
    }
}