I'm trying to make a scheduling tool for my major at my school and I have a CourseEntryForm , RemainingCourse sForm and CoursesCompelte dForm.

The CourseEntryForm has list boxes of courses that are required for graduation. I have been able to send the selected values of these list boxes to rich text boxes in the CoursesComplete dForm, however I need the courses that have not been selected in the list boxes to be sent to string that I...