private void btnLogin_Click(object sender, EventArgs e) { if (!this._IsEmailValid(tbIndexLoginEmail) || !this._IsIndexLoginPasswordValid()) { this._CheckIndexLoginEmailValidation(); this._CheckIndexLoginPasswordValidation(); return; } // Start Database Login process string email = tbIndexLoginEmail.Text.Trim(); string password = tbIndexLoginPassword.Text.Trim(); string type = gbIndexLoginUserType.Controls.OfType <RadioButton>().FirstOrDefault(rb => rb.Checked).Text.Trim(); dynamic user = null; if (type.Equals("Student")) { user = new Tenant(); } else if (type.Equals("Renter")) { user = new Renter(); } else if (type.Equals("Admin")) { user = new Admin(); } user.Email = email; user.Password = password; user = IndexController.AuthenticateUser(user, this); this._ResetIndexLoginInputs(); if (user == null) { // Displays the MessageBox. MessageBox.Show( "Login Credential is not correct", "Error Login", MessageBoxButtons.OK, MessageBoxIcon.Information ); } }