private void removeBTN_Click(object sender, EventArgs e) { COURSE course = new COURSE(); int cID = Convert.ToInt32(textBoxCId.Text); if (course.deleteCourse(cID)) { MessageBox.Show("Delete Course Successfully", "Delete Course", MessageBoxButtons.OK, MessageBoxIcon.Information); } else { MessageBox.Show("Error", "Delete Course", MessageBoxButtons.OK, MessageBoxIcon.Error); } }