Grabbing User ID From Vanilla to set session

[eluser]Unknown[/eluser]
Hey guys,
I've installed my vanilla in forum directory and codeigniter in root directory of my website

i want my codeigniter website to grab userid of user logged in in vanilla so that it can show logout buttor and username so how can i grab vanilla session data in codeigniter?

Please easy method

[eluser]Tpojka[/eluser]
You have to be connected to vanlla user session table for that.
Connect to it and grab data from session table where is marked user as logged_in or not.
I have no experience with vanilla forums, but this is just way you should try.