chapter and part titles

[Hraban <angerweit@gmx.net>]

(1)
I look for a possibility to tell ConTeXt to use a shorter version of a
chapter title for the header and for the table of contents, such like

\chapter[ref:chapter][The long chapter]{This is a very, very long
chapter}

The text in {} should form the title, where the chapter begins,
and the second [] is, what's to be used for header and toc.

How can I do that?

(2)
I want to layout my part start pages as follows:
- a papersized picture in the background
- Text e.g.: "Part IV: The end"
- a motto, that shouldn't appear in the toc

I tried (without the third item):

\useexternalfigure[hintergrund][part][]
\defineoverlay[titelbild]
[{\externalfigure[hintergrund][width=\overlaywidth,height=\overlayheight]}] 
\setupheads[\x03]
\setuphead[part][style=\tfd\it, page=right, header=empty,
background=titelbild, number=yes, align=left, numberstyle=Romannumerals,
right={: }]

That's not working. How would it work?

(I'd satisfied, if you could point me to the right commands,
I'll then try the right syntax myself -- it's a bit heavy
to find the right thing in the beta manual, if I don't know
what to look for...)

thank you again!

hraban.

\x1a