private void Add_Course_Button(object sender, RoutedEventArgs e) { if (CourseNumberTB.Text == "" || courseNameTB.Text == "" || MeetingTimeTB.Text == "" || DateOfCourse.SelectedDate == null) { MessageBox.Show("Please enter all information"); } else { FileReadWrite file = new FileReadWrite(); int courseNum = Convert.ToInt32(CourseNumberTB.Text); string courseName = courseNameTB.Text; string meetingTime = MeetingTimeTB.Text; DateTime courseDate = (DateTime)DateOfCourse.SelectedDate; Course course = new Course(courseNum, courseName, meetingTime, courseDate); student.AddCourse(course); file.AddCourseToFile(student, course); ViewCourses viewCourse = new ViewCourses(student); this.Close(); viewCourse.Show(); } }