private void Button_Click(object sender, RoutedEventArgs e)
 {
     //The following code takes data from the combobox and TextBox and inserts it into the SQL Enrollment Table.
     try
     {
         int courseId;
         if (EnrollCourseComboBox.SelectedValue != null)
         {
             courseId = (int)EnrollCourseComboBox.SelectedValue;
             bool isEnrolled = studentBL.EnrollInCourse(student.StudentID, courseId);
             if (isEnrolled)
             {
                 MessageBox.Show("Enrolled Successfully");
             }
             else
             {
                 MessageBox.Show("Failed to enroll!", "Error", MessageBoxButton.OK, MessageBoxImage.Error);
             }
         }
         else
         {
             MessageBox.Show("Please Select A course!", "Error", MessageBoxButton.OK, MessageBoxImage.Error);
         }
     }
     catch (Exception ex)
     {
         MessageBox.Show("Already Enrolled!", "Error", MessageBoxButton.OK, MessageBoxImage.Error);
     }
 }