Why doesn't callback work?

Question

OOP

setAuth: ( some, cb) ->		
  if !some
    @getlogin = 
      response: 'not found'
      object: 'user'
  else
    @getlogin = 
      response: 'success'
      object: 'user'
      data: getLogin
  cb @getlogin

I call it like this:
setAuth( some, (cb)->
res.send cb
)
As a result, @getlogin gives undefined on the first page refresh, and an object on the second one...