Question about X-Windows and Perl

["Jason B" <surreal_world at hotmail dot com>]

I am currently working on a program for school that I must write in Perl.  
The program is to code something that will create a new X-Windows 
application.  Inorder to test my program I need to use an X-Windows 
environment, I installed CygwinX and when I run my perl code using the 
following command
 perl tkdemo.pl
the following error appears
Can't locate Tk.pm in @INC (@INC contains: /usr/lib/perl5/5.8/cygwin 
/usr/lib/perl5/5.8 /usr/lib/perl5/site_perl/5.8/cygwin 
/usr/lib/perl5/site_perl/5.8 /usr/lib/perl5/site_perl/5.8 
/usr/lib/perl5/vendor_perl/5.8/cygwin /usr/lib/perl5/vendor_perl/5.8 
/usr/lib/perl5/vendor_perl/5.8 .) at tkdemo.pl line 3.
BEGIN failed--compilation aborted at tkdemo.pl line 3

I know for a fact the code is correct as it runs perfectly fine on the 
school Unix boxes.  I however have a windows box, and cannot seem to get 
this work.  Any and all help will be greatly appreciated.

Thank you