Text Formatting ⇒ Removing period/full stop in section titles

[jodles]

I want the subsections and the subsubsections in my document to be numbered as (example):
a) subsection
(i) subsubsection
(ii) subsubsection

In the preamble (I'm using Lyx), I've put:
\renewcommand{\thesubsection}{\alph{subsection})}
\renewcommand{\thesubsubsection}{(\roman{subsubsection})}

But this produces the following output:
a). subsection
(i). subsubsection
(ii). subsubsection

How can I remove the dots? I often find myself moving into TexShop before finishing a document, so I'm not limited to Lyx!

Is there any document class that numbers the sections in that manner (if there's no way around it)?

[frabjous]

You can probably get around it by loading titlesec package in the preamble and using some of its commands, but it would help to know why you're getting these in the first place, since you wouldn't with the standard document classes. What document class/LyX template are you using as is?

[jodles]

I see! I'm using the article (AMS). What are the standard classes?

[jodles]

I checked a little by myself now, and what LyX calls simply "article" seemed to work fine. The fonts and layout is slightly different of course, but I might be able to stay with that for this paper...

I'll have to look closely at the titlesec package at some time! Seems like it comes around every time I'm stuck!:P