Unregistering from Courses
When you hit "Register for Courses" and the page is first displayed, the Selected Courses area shows all courses for that term in which you are currently registered. In most cases you may unregister from courses in which you are currently registered by clicking the icon next to the desired course in the Selected Courses area. You will be unregistered from the course as indicated by the course being removed from the Selected Courses area and returned to the Required Courses area.
After clicking on the button gives you.