private void AddCourseBtn_Clicked(object sender, EventArgs e)
 {
     try
     {
         if (string.IsNullOrWhiteSpace(CourseIDCell.Text) || string.IsNullOrWhiteSpace(CourseNameCell.Text) || string.IsNullOrWhiteSpace(CourseViewCell.Text))
         {
             DisplayAlert("Error", "Please input correct data", "OK");
         }
         else
         {
             if (CourseStartDate.Date > MainPage.term.StartDate && CourseStartDate.Date < MainPage.term.EndDate && CourseEndDate.Date > MainPage.term.StartDate &&
                 CourseEndDate.Date < MainPage.term.EndDate && CourseStartDate.Date < CourseEndDate.Date)
             {
                 int      courseID     = Convert.ToInt32(CourseIDCell.Text);
                 int      termID       = Convert.ToInt32(TermIDCell.Text);
                 string   courseName   = CourseNameCell.Text;
                 DateTime startDate    = CourseStartDate.Date;
                 DateTime endDate      = CourseEndDate.Date;
                 string   courseStatus = CourseStatusPicker.SelectedItem.ToString();
                 string   courseView   = CourseViewCell.Text;
                 string   courseNotes  = CourseNotesCell.Text;
                 WGU.AddCourse(new Course(courseID, termID, courseName, startDate, endDate, courseStatus, courseView, courseNotes, WGU.Instructor, new ObservableCollection <Assessment>()));
                 Navigation.PopAsync();
             }
             else
             {
                 DisplayAlert("Error", "Invalid Dates, Please Make sure your dates are correct.", "OK");
             }
         }
     }
     catch (FormatException ex)
     {
         DisplayAlert("Error", ex.Message, "Okay");
     }
     catch (ArgumentNullException n)
     {
         DisplayAlert("Error", n.Message, "OK");
     }
 }