public void useLoginButtonAction() {
        String enteredUserName = userIdTextField.getText();
        char[] pass = passwordPasswordField.getPassword();
        String enteredPassword = new String (pass);
        if(hospital.getAllUsers().containsKey(enteredUserName)) {
            String realPassword = hospital.getAllUsers().get(enteredUserName).getPassword();
            if(realPassword.equals(enteredPassword)) {
                goToUserPage(enteredUserName);
                return;
            } else {
                System.out.println("Wrong Password");
                clearTextFields();
                return;
            }
        }

        if(hospital.getAllStaff().containsKey(enteredUserName)) {
            String realPassword = hospital.getAllStaff().get(enteredUserName).getPassword();
            if(realPassword.equals(enteredPassword)) {
                goToAdminPage(enteredUserName);
                return;
            } else {
                System.out.println("Wrong Password");
                clearTextFields();
                return;
            }
        }

        System.out.println("Wrong User Name.");
    }