private List <Course> getClasses()
        {
            List <Course>       coursesToAdd = new List <Course>();
            ClassSelectorWindow csWindow     = new ClassSelectorWindow(this.loader);
            bool?dialogResult = csWindow.ShowDialog();

            switch (dialogResult)
            {
            case true:
                coursesToAdd = csWindow.selectedCourses();
                break;

            case false:
                break;

            default:
                break;
            }
            return(coursesToAdd);
        }
        private void Prereqs_Selector_Button(object sender, RoutedEventArgs e)
        {
            ClassSelectorWindow csWindow = new ClassSelectorWindow(this.loader);
            bool?dialogResult            = csWindow.ShowDialog();

            switch (dialogResult)
            {
            case true:
                if (prereqs == null)
                {
                    prereqs = csWindow.selectedCourses();
                }
                else
                {
                    prereqs.AddRange(csWindow.selectedCourses());
                }
                break;

            case false:
                break;

            default:
                break;
            }
            listOfPrereqs.Text = "";
            if (prereqs != null)
            {
                for (int i = 0; i < prereqs.Count; i++)
                {
                    if (i == prereqs.Count - 1)
                    {
                        listOfPrereqs.Text += prereqs[i].courseNumber;
                    }
                    else
                    {
                        listOfPrereqs.Text += prereqs[i].courseNumber + ", ";
                    }
                }
            }
        }