Hi I am one of the experts here on Just Answer.comYou are correct in that you can have more than one skype account. Essentially what happens with skype is it automatically signs in with the last account that logged into when the program boots up it if that is what your settings are set it. You could simply log out of the skype program and login with your second account to access that one.
You will also notice if you have signed into skype with the different accounts on the same computer the drop down for the username section will show the multiple logins
Once you sign out the screen where you can sign in there should be a setting under preferences to disable autosign in
Since you were offline I switched the question to Q&A format so it wouldn't time out
Please let me know if you have any questions.