Need Robustness Diagram for the use case text below:

Basic Course

The student views the Grad Check Home Page and clicks on the Edit Schedule button. The system then displays the Current Student Schedule. On this page, the student may then choose a course to delete a course or to add a course. After the student performs these tasks, the system asks the user to save the changes on the Save Changes page. If the student selects Yes, the system updates the student record file. Otherwise, the student record is not updated.

Alternate Course

The student record file is unavailable: display Unable to Save page to the Student.