...
To log out of My WebEx, you must close your browser. If that doesn't work, follow these instructions from CIT...
"Generally, when a browser exits it should log you out of the CU Web Login, which WebEx uses. Your browser may have been running in the background after you exited out. In order to logout in this situation, you can delete all the cookies on your browser by following these directions: http://www.aboutcookies.org/default.aspx?page=2."