btnSingin.setOnAction(new EventHandler<ActionEvent>() {
        @Override
        public void handle(ActionEvent t) {
            Connection conn ;
            ResultSet rs ;
            PreparedStatement pst ;
            conn = SQLConnection.connectDB();
            String sqlString = "select * from Admin where username=? and password=? ";

            try {
                pst = conn.prepareStatement(sqlString);
                pst.setString(1, txtUsername.getText());
                pst.setString(1, txtpassword.getText());
                rs = pst.executeQuery();
                if (rs.next()) {
                    JOptionPane.showMessageDialog(null, " Username And Password Was Correct ");
                } else {
                    JOptionPane.showMessageDialog(null, " Username And Password Not Was correct . . . ");
                }
            } catch (Exception e) {
                System.out.println(e);
            }
        }
    }
    );