Media, Add Share Issue, what are the login & password?

When I select MEDIA, Add Share, I see my iMac and Mac Book

When I select them it ask me a login and password, what should I enter?

Same here, when i add share, just see Apple TV and no other resources in my network, btw is windows workgroup

any clue

 

TIA

To make it work, i went to my system preferences, clicked "Sharing" then clicked and ticked the "file sharing" option on the menu on the left. Once i'd done this i clicked the option box on the right. Once in that window i ticked "share files and folders using AFP. My login and password are exactly the same as my mac's login and password. 

Hope this helps. Good luck!