How to logout from Skype to relogin under other name? How to logout from Skype to relogin under other name?

I mean skype for pad-sized computers.

If I press avatar, then I have "exit" entry at the bottom. But if I click this entry, then Skype just closes. If I open it again, then it enters under old name again.

I want to logout so that it ask password.

Is it possible?
Click on the avatar button on the top right of the app. Once you click there click on the option menu (three vertical dots) and click on sign out. 
It works pretty much the same for every single Skype UI (iOS and Windows client).