private void RegisterButton_Click(object sender, RoutedEventArgs e)
        {
            // Get the Form inputs values:
            String username, email, password;

            username = RegisterUsername.Text;
            email    = RegisterEmail.Text;
            password = RegisterPassword.Password.ToString();

            // Check if any of the value was missed
            bool isFormValid = ValidateRegisterForm(username, email, password);

            // If Form is valid add new user to database:
            if (isFormValid)
            {
                // Build a new user and add it to the database:
                UserBuilder builder = new UserBuilder();

                builder.SetEmail(email).SetUsername(username).SetPassword(password);
                User newUser = builder.Build();

                userRepo.Add(newUser);
                userRepo.Save();

                MessageBox.Show($"{username} created!");

                // Redirect user to the Task Mamanger:
                TaskCreation tc = new TaskCreation(newUser);
                tc.Show();
                this.Close();
            }
        }
        private void LoginButton_Click(object sender, RoutedEventArgs e)
        {
            // Get the Form inputs values:
            String email, password;

            email    = LoginEmail.Text;
            password = LoginPassword.Password.ToString();

            User user = CheckIfUserExists(email);

            // CHECK IF USER PASSED CORRECT VALUES:
            if (user == null)
            {
                MessageBox.Show("Incorrect username or password!");
            }
            else if (user.Password == password)
            {
                MessageBox.Show("Logging in...Click OK");
                TaskCreation taskCreation = new TaskCreation(user);
                taskCreation.Show();
                this.Close();
            }
            else
            {
                MessageBox.Show("Incorrect username or password!");
            }
        }