[Q] (newbie) typesetting to grid in layer with widgets

["Rolf Marvin B e Lindgren" <r.m.b.lindgren@usit.uio.no>]

[firt message still waits for moderator approval, here's a new and
improved version]

I'm giving ConTeXt  a first go in typesetting a diploma.  

I've figured out that I'd like to try to typeset to a five-column grid.

Most of the stuff should be centered against the third column, while
some stuff should be centered to the second and fourth column.

This makes for a very boring diploma, but that's beside the point at
this stage.

I want 1-inch borders throughout, so before \starttext, I have 

\setuplayout[paperheight=29.97cm,paperwidth=21cm,leftmargin=1cm,rightmargin=1cm,header=1cm,footer=1cm,textwidth=19cm,textheight=27.97cm]

(I pretend that marginpars don't exist.  I'm sure they'll come back and
haunt me).

Furthermore, before \starttext, I set up the layers I think I need with

\setuplayout[grid=yes,columndistance=12pt,columns=5]\showgrid
\definelayer [text] 
\setupbackgrounds [text] [background=text]

(The showgrid is there because I like to see what I'm doing).  Then I
have, say,

\setlayer[text][column=3,line=7,x=0.5\layoutcolumnwidth,location=c]{%
       Diploma awarded to}


now, _is_ this the smartest way to do this? 

furthermore, I'd like to allow for input into fields from Acrobat.  I
have this:

\definefield[CertID][text][CertIDSetup][]
\setupfield[CertIDSetup][%
        readonly=no,printable=yes,width=4em,%
        frame=on,height=8mm,offset=5ex]

\myCenter{3}{11}{Sertifikat Nr. DNV-2004-OSL-PERS-\field[CertID]}

trouble is, the _field_ is aligned to the baseline, whereas I'd like
the text _of_ the field to be thus aligned.  any suggestiosn?

(as a matter of fact, the problem with this approach is that text
cannot ever be centered becaue TeX need to know the dimensions at
typesetting time - which isn't known until the user has interacted.  is
there, say, JavaScript magic that could be done in order to have text
centered after it has been input?

and on a sitenote,

I'd like to have a frame around the entire page.  Preferably, I'd like
to be able to place it using numerical coordinates (absolute or
relative, set to a layer or not).  Is this, or something close to it,
possible? 

thank you,

-- 
Rolf Lindgren                                            http://www.roffe.com/
roffe@tag.uio.no