public void CreateMethod()
        {
            //If any of the properties are null, there was a problem loading the variables
            if (ClassName == null && DateDue == null && Importance == null)
            {
                throw new InvalidOperationException($"{nameof(ClassName)}, {nameof(DateDue)} or {nameof(Importance)} is null");
            }

            DateTime formatDateDue;

            try
            {
                //Convert the date String into type DateTime
                formatDateDue = DateTime.Parse(DateDue);
            }
            catch (Exception ex)
            {
                //String was in a incorrect format
                throw new FormatException("The Date Due was in a bad format", ex);
            }

            //Retrieves the letter from the end of the Course, this determines which semester the class is in
            var    charArray   = ClassName.ToArray();
            var    getSemester = charArray.Last();
            string semester;

            switch (getSemester)
            {
            case 'a':
                semester = "1st";
                break;

            case 'b':
                semester = "2nd";
                break;

            default:
                semester = "NA";
                break;
            }

            var addClass = new DueItem()
            {
                Class       = ClassName,
                Semester    = semester,
                Date_Due    = formatDateDue,
                Importance  = Importance,
                Description = Description
            };

            using (databaseConnection = new CoursesEntities1())
            {
                databaseConnection.DueItems.Add(addClass);
                databaseConnection.SaveChanges();
            }

            Refresh();
        }