Login / Logout / loggedinuser

hi all! I think I am doing a mess here. I need to have: 1) a Login link if there is no user logged. Something like *Login>.|command=Login* 2) a Logout if there is a logged user. Something like *Logout>.|command=Logout* 3) Display something like what does loggedinuser (Logged in as +value:user+ (+widget+?)) 4) a Register link if there is no user logged. This is to create a new user. But I want all of them ;) Is there a way of put like ifs in a page ? just to know if there is a user logged. Can I do this just with Pier as it is now or I need to extend, modify or create something ? Thanks! Mariano