Template Hook Avatar

[Kriskof]

Hi, I'm currently using 3.8.7 and want to display and switch the user's avatar on the side of the template when they change it but can't seem to get it to work.

I'm currently using:

<img src="image.php?u=$bbuserinfo[userid]">

This displays their current avatar, but the image stays the same even if they change avatars or even logout and log back in. I want it to change when they change their avatar. I read that you need can use a template hook to get this done, but I can't find the solution for it. If anybody can help, that'd be great. Thanks.