ert - 2018-01-03

I would like to execute certain functions upon any user login/logout.

In Task Configuration there seem to be some useful Event Handlers: System Events -> Add Event Handler.
I added:
- event Login, function to call TestLogin
- event Logout, function to call TestLogout

Afterwards I get compile errors "Function TestLogin/TestLogout requires exactly '0' inputs".

How to use the Login/Logout events then?
Are the System Event Handlers and their usage documented anywhere?