beginner's hazzles with backgrounds and definitions.

[Matthias Weber <matweber@indiana.edu>]

Hi,

I am new to context, migrating from latex for the purpose of writing an
online book. I would like to set up a few definitions in the 
environment file
that would replace latex's  \begin{definition} ... \end{definition}
environments. I realize that this can  be done conveniently with 
\defineenumeration,
but I want of course a few more features in it then in latex's setup. 
For example, I'd like to have the
definition typeset in some color against some background. I tried the 
following
in the environment file:

\setupcolors[state=start]

\definetextbackground
[defbackground]
[backgroundcolor=blue,
backgroundoffset=.25cm,
offset=.25cm,
frame=off,
location=paragraph,
color=green]

\defineenumeration
[definition]
[text=Definition,
location=left,
before={\starttextbackground[defbackground]},
after={\stoptextbackground},
letter=it]

Then, in the text, when I use

\startdefinition
This is my definition.
\stopdefinition

the text comes out green all right, but the blue background is  smeared 
all over two pages.
I have tried a few modifications to no avail, so I fear I am doing it 
all wrong.

Curiously, when I typeset the above th first time, I only get the green 
text (no blue), and the
mess shows only up when typesetting the second time.

Any help?

Thanks,

Matthias