Xemacs 21 instellation problem

[Micha Feigin <michf@math.tau.ac.il>]

I Installed xemacs 21 on my computer together with xemacs20 and it worked
fine.
I then removed xemacs 20 to free the space and xeamcs stoped working.
I tried to reinstall it from scrach but i kept getting an error massage
from apt-get (smae message i got when i tried to start it after removeing
xemacs20):

Couldn't find obvious defaults for:
doc-directory
data-directory
exec-directory
Perhaps some directories don't exist, or the XEmacs executable,
/usr/bin/xemacs21
is in a strange place?
xemacs exiting.Cannot open load file:
/home/dres/project/debian/xemacs21/xemacs-21.1.2/lisp/auto-autoloads
make: *** [lisp/auto-autoloads.el] Error 255
emacs-install: /usr/lib/emacsen-common/packages/install/x-symbol xemacs21
failed at /usr/lib/emacsen-common/emacs-install line 28.

Thanx
michf@math.tau.ac.il