I am building a custom order entry screen for our business. It integrates with our backend system, and is all custom code, developed outside of C5.
We are using C5 for the rest of the website content. I want to use the C5 User Login system to allow our clients access to their own data within my custom stuff.

What is the bare minimum I need to get access to the Logged In User's information? I don't want to just start throwing requires around. I don't care about OO functionality. All I need is which C5 scripts will allow me to query the user information from C5's user table, and what in the session or cookie tells me the user that is logged in.

Thanks a lot. If this is documented, I appologize for not finding it.