I am new the Sandbox environment, I am trying to test some of the WebEx API's however when setup my first reservation I created a user account. Now when I create a new reservation as the old one has expired I cannot use the same details as before for the user account. Keeps saying it is being used. What I am not sure is how do I use the previous account I created? Or do I need to create a new account everytime I create a new reservation for WebEx?