On Sat, 10 Jul 2010 08:53:42 +0200, Jordi Inglada <jordi.inglada@cesbio.cnes.fr> wrote:
> 
> Eric,
> 
> Thanks for your reply. Now I understand.
> 
> The advice function is now called when I add a diary entry, however,
> when I load emacs I get this message:
> 
> Warning: reference to free variable `d1'
> 
> And when I add a diary entry, I get an error message like this:
> 
> org-agenda-diary-entry-in-org-file: Wrong number of arguments: 

[...]

 [ad-return-value d1 dates
> entry d2 day1 nil
> ad-Orig-org-agenda-add-entry-to-org-agenda-diary-file 2 block ...] 17
> #("Advice doc string" 0 17 (ad-advice-info
> org-agenda-add-entry-to-org-agenda-diary-file))], 3
> 
> 
> I am not sure to use the right syntax for the diary entry.

I think this is more than likely due to you using a older version of
org mode.  What version are you using?  (try "M-x org-version RET").