If you do not know your student ID, you will need to log into banner (the website where you registered for courses) http://www.gtc-web.org. Once logged in, click "Personal Information" --> "View E-mail Address(es)/ Blackboard Learning Management System User ID"
Your 900# is located under "Angel Account" or "Blackboard account" at the bottom along with your email address. (Note: The information for Blackboard on this page is incorrect.)