public class LoginController {

	@FXML	AnchorPane mainPane;
	@FXML	AnchorPane secondaryPane;
	@FXML	Button loginButton;
	@FXML	Button toSignUp;
	@FXML	PasswordField passwordField;
	@FXML	TextField usernameField;

	static String file = "info.txt";
	static Scanner scanFile = new Scanner(file);
	static Stage secondaryStage;


	public void buttonClickedHandler (ActionEvent evt) {
		Button clickedButton = (Button) evt.getTarget();
		String buttonLabel = clickedButton.getText();

		if(loginButton.getText().equals(buttonLabel)) {
			String username = usernameField.getText();
			String password = passwordField.getText();
			boolean found = verifyLogin(username,password,file);
			if (found) {
				openWindow("loginSuccess", 350, 150);
			}
		}
		if(toSignUp.getText().equals(buttonLabel)) {
			openWindow("SignUp", 600, 400);
		}
	}

	 void openWindow(String name, int width, int height) {
		try {
			// load the pop up you created
		Pane pane = (Pane)FXMLLoader.load(getClass().getResource(name + ".fxml"));

				// create a new scene
		Scene scene = new Scene(pane,width,height);

		//select corresponding stylesheet to correct window
		scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());

		//create new stage to put scene in
				secondaryStage = new Stage();
				secondaryStage.setScene(scene);
				secondaryStage.setResizable(false);
				secondaryStage.showAndWait();

				} catch(Exception e) {
					e.printStackTrace();
				}
			}


	boolean verifyLogin(String username, String password, String filepath) {

		boolean found = false;
		String tempUsername = "";
		String tempPassword = "";

		try {
			scanFile = new Scanner(new File(filepath));
			scanFile.useDelimiter("/");

			//While loop read each line from designated file for the records of usernames and passwords
			//and save each password and username in temp strings below
			while (scanFile.hasNext() && !found) {
				//System.out.println("ok");
				tempUsername = scanFile.next();
				tempPassword = scanFile.next();

				if (tempUsername.equals(username) && tempPassword .equals(password)) {
					found = true;
				}
			}
			scanFile.close();
			System.out.println(found);
		}
		catch(Exception e) {
			System.out.println("Error");

		}
		return found;
	}
}



*********************************************SIGNUP************************************


public class SignUpController {
	@FXML	Button SignUpButton;
	@FXML	TextField EnterUsername;
	@FXML	PasswordField EnterPassword;
	@FXML	PasswordField reEnterPassword;
	@FXML	Text PassError;
	@FXML	Text PassError1;
	@FXML	Text UserExists;

	static String file = "info.txt";
	static Scanner scanFile = new Scanner(file);
	static Stage secondaryStage;


	public void buttonClickedHandler (ActionEvent evt) throws IOException {
		Button clickedButton = (Button) evt.getTarget();
		String buttonLabel = clickedButton.getText();

		if(SignUpButton.getText().equals(buttonLabel)) {
			String newUsername = EnterUsername.getText();
			String newPassword = EnterPassword.getText();
			String checkPassword = reEnterPassword.getText();
			if (newPassword.equals(checkPassword)) {
				boolean requiredPassword = checkPassword(newPassword);
				if (requiredPassword) {
					boolean done = checkCredentials(newUsername, newPassword, checkPassword, file);
					if (!done) {
						closeCurrentWindow(evt);
					}
				}
			}
		}
	}


	private boolean checkPassword(String password) {
		boolean meetsRequirments = false;
		char ch;
		for (int i = 0; i < password.length(); i++) {
			ch = password.charAt(i);
			if (Character.isUpperCase(ch)) {
				meetsRequirments = true;
			}

		}
		if (!meetsRequirments) {
			PassError.setVisible(true);
			PassError1.setVisible(true);
		}
		return meetsRequirments;
	}


	boolean checkCredentials(String newUsername, String newPassword, String checkPassword, String filepath) throws IOException {
		boolean userExists = false;
		try {
			String tempUsername = "";
			String hold = "";
			scanFile = new Scanner(new File(filepath));
			scanFile.useDelimiter("/");


			//While loop read each line from designated file for the records of usernames and passwords
			//and save each password and username in temp strings below
			while (scanFile.hasNext() && !userExists) {
				//System.out.println("ok");
				tempUsername = scanFile.next();
				hold = scanFile.next();

				if (tempUsername.equals(newUsername)) {
					userExists = true;
				}
			}
			scanFile.close();

			if (userExists) {
				UserExists.setVisible(true);
			}
		}
		catch(Exception e) {
			System.out.println("Error");
		}

		if (!userExists) {
			addCredentials(newUsername, newPassword, file);
		}
		return userExists;
	}


	private void addCredentials(String newUsername, String newPassword, String file) throws IOException {
		FileWriter fw = new FileWriter(file, true);
		fw.write("/"+newUsername+"/"+newPassword);
		fw.close();

	}

	private void closeCurrentWindow(ActionEvent evt) {
		final Node source = (Node) evt.getSource();
		final Stage stage =(Stage)source.getScene().getWindow();
		stage.close();
	}
}