private void btnSubmit_Click(object sender, EventArgs e) { if ( this.txtFirstName.Text != "" && this.txtLastName.Text != "" && this.txtEmail.Text != "" && this.txtProfession.Text != "" ) { MessageBox.Show(TeacherClass.addTeacher(this.txtFirstName.Text, this.txtLastName.Text, this.txtEmail.Text, this.txtProfession.Text), "Information", MessageBoxButtons.OK, MessageBoxIcon.Information); ClearInput.clearInput(this); } else { MessageBox.Show("Tous les champs doivent être remplis", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information); } }