killing jobs in C-shell scripts

Hi all,
I'd like to know how to run and kill jobs in a c-shell scripts..
I mean: last week I tried to run this simple script:

#! /bin/csh

donalduck &

sleep 60


kill %1


the problem is that sometimes it' s not able to stop the background script (donalduck running job not found).
I' ve tried to substitute the line : "kill %1" with "kill -9 %1"
or "kill <pid>" or "kill -9 <pid>", but the behaviour is the same!!
Moreover it seems that the problem is only present in c-shell
scripts because I ran the same script using Ksh and it worked always well.

Can anybody explain me the different behaviuor from the two shell?? Is there any other mechanism I can use inr C-shell to overcome the problem?

Thanks for the support!

imo
the best cmd-line shell: csh
the worst script shell: csh
csh (in script) is buggy, bsd joungs did not finish the job
don't use csh for scripts, if you want sure they work on EVERY
*nix use bourne.
if you need more infos, google for csh scripts, a lot of papers.