clearing past accounts you've logged in to

skypeenglish at (Sarah k Alawami via Skypeenglish)...

Hello to all. running latest skype on osx 10.3. Anyway, how do I clear past log ins? I'm a sub for a service that works with students and I have to log in using a different account each time. I don't want to see these accounts as I always clear the emails so I don't accidentally use that one again. but the user name will still stay in my skype sign in list. Advice here?