private void courseDeleteButton_Click(object sender, EventArgs e)
 {
     ob = new Gateway();
     if (ob.DeleteEntireRowOfCourseTable(courseNoTextBox.Text) == 1)
     {
         MessageBox.Show("Deleted Successfully!");
         courseResetButton_Click(sender, e);
     }
     else if (ob.DeleteEntireRowOfCourseTable(courseNoTextBox.Text) == 2)
     {
         MessageBox.Show("You will can not delete this foreign key item!");
     }
     else
     {
         MessageBox.Show("Could not delete!");
     }
 }