private void btn_RegisterInRegisterForm_Click(object sender, EventArgs e) { string _email = txb_EmailInRegisterForm.Text; if (!string.IsNullOrEmpty(this.txb_Name.Text) && !string.IsNullOrEmpty(this.txb_Surname.Text) && !string.IsNullOrEmpty(this.txb_PhoneNumber.Text) && !string.IsNullOrEmpty(this.txb_EmailInRegisterForm.Text) && !string.IsNullOrEmpty(this.txb_PasswordInRegisterForm.Text) && !string.IsNullOrEmpty(this.txb_PasswordAgain.Text) && txb_PasswordInRegisterForm.Text == txb_PasswordAgain.Text && myDatabase.EmailChecking(_email)) { User user = new User() { Name = txb_Name.Text, Surname = txb_Surname.Text, Email = txb_EmailInRegisterForm.Text, PhoneNumber = txb_PhoneNumber.Text, Password = txb_PasswordInRegisterForm.Text }; myDatabase.UserAdd(user); MessageBox.Show("Completed"); } else { MessageBox.Show("Failed"); } }