using AMS Article style

[Tony Dancer]

I'm using the AMS Article style, mostly because I like the look.
However, I would like to modify the style so that there is a return
after each subsection and subsubsection - at the moment the text flows
one the same line as these sub-headings. Can anyone offer any pointers
as to how to change this (which i guess is another way of asking about
how one creates styles?) ?

Thanks
Tony