perl/tk problem

[Marco Prandini <prandini@comune.modena.it>]

Hello,
I'd like to write some code with perl5's Tk module, but I've been
stopped two seconds after my first try:

	Can't find loadable object for module Tk in @INC 	
(/usr/lib/perl5/i486-linux/5.003 /usr/lib/perl5 /usr/
	local/lib/site_perl/i486-linux /usr/local/lib/site_perl .) 	at
/usr/lib/perl5/Tk.pm line 35
	BEGIN failed--compilation aborted at ./tk.pl line 4.

where tk.pl is the sample suggested in /usr/lib/perl5/Tk/UserGuide.pod:

	#! /usr/bin/perl5 -w
	
	        use strict;
	        use Tk;
	
	        my $main = new MainWindow;
	        $main->Label(-text => 'Hello, world!')->pack;
	        $main->Button(-text => 'Quit',
	                      -command => sub{exit}
	                      )->pack;
	        MainLoop;

Apparently both perl and Tk4.1 are correctly installed 
(from the corresponding debian packages), so...
can anyone suggest me what is the missing "loadable module",
where is it and where should it be ?

	TIA,
	 Marco.