Ok i removed \definefont and \Dings :
It works now !

I’ve got two last questions:
how can I make starting the head at the backspace (in margin) but continuing in text? 
where can i find documentation about hbox,hfill etc. ?

Thanks

From: ryzz@hotmail.fr
To: ntg-context@ntg.nl
Subject: Re: [NTG-context] modify resume
Date: Wed, 22 Sep 2010 13:55:12 +0200

I’m sorry but it still don’t work.
I add "\usesymbols[mvs]" but i have this message:

! Font \**Dings**:=MarVoSym at 8.00003pt not loadable: Metric (TFM) file not fo
und.
<to be read again>
                   \relax
\definefontlocal ...ndcsname \lastfontname \relax
                                                  \expandafter \let \expanda...

\dododefinefont ...ontspec {#2}\rawfontidentifier
                                                  \let \localrelativefontsiz...

\redodefinefont #1#2#3->\dododefinefont {#1}{#2}
                                                \doifsetupselse {#3} {\setup...

\placehead ...} \hbox {\addressb } \hbox {{\Dings
                                                  B} \email } \hbox {{\Dings...
l.14 \placehead

I think this line is suspect:
\definefont[Dings][name:MarVoSym]
Why "name:" ?