[Lazarus] Grouping radio buttons

[Jürgen Hestermann]

I already searched for hours but cannot find anything useful.

My question:
Is it possible (and if yes, how) to group some radio buttons
so that only one of each group can be selected?

I put some radio buttons on my form which select different things
but they are all connected with each other so that only one can be 
selected at a time.

I expected some property defining a goup but I cannot find anything like 
that.