private void TxtUserEmail_TextChanged(object sender, EventArgs e) { AppUser appUser = new AppUser() { UserName = txtUserName.Text, UserPassword = txtUserPassword.Text, UserEmail = txtUserEmail.Text }; bool checkSignUp = signUpController.UserSignUpEmailControll(appUser); if (checkSignUp) { lblEmailCheck.Text = "Valid Email Format"; lblEmailCheck.ForeColor = Color.Green; } else { lblEmailCheck.Text = "Invalid Email Format!"; lblEmailCheck.ForeColor = Color.Red; //MessageBox.Show("Error!"); } }