Garry's Mod Group [Steam]

I bought Garry’s Mod already, why I’m not in THIS group?
Anyone have any ideas what I should do to join that group?

Click the join button on the top right of the page?

Joining steam groups is optional, it does not put you in by default.

Click join…

Thanks but there is no button there, anyway please help me here first: http://www.facepunch.com/threads/1061321-Random-Crash!