My b2evolution Version: Not Entered

This is a little complicated, i need to determine which blog the user is writing in, im trying to edit a plugin that doesnt do this and want to know what php file do i need to include and what variable would get me the string of the blog.

Example

Joe is writing in blog1 named pizzablog
there has to be a php file holding the info joe is writing in pizzablog.

Then i want to import that data into my conf file for this plugin which would then help me out in my uploads which would fix this
/media/blogs/'.$joescurrentblog.'/'; something like that which would give.
/media/blogs/pizzablog/ as its upload :)

thanks for anyone who can help me, i did find the selectedblog variable in the admin.php but it returns i think an int.