help building DDD on windows XP platform

[Mike Hansen]

I'm trying to build and use DDD within Cygwin on my Windows XP machine.  I'm
following the steps as given at:
http://www.gnu.org/software/ddd/

i.e.
The simplest way to build DDD is: 
        Unpack the DDD source distribution 
        Change into the ddd-version subdirectory 
        Type ./configure; make 

I unpacked the DDD source distribution in my cygwin directory.  I changed to
directory ddd-3.3.9.  I type ./configure.  It runs for awhile and I
eventually get this error message:
configure: error: The X11 library '-lX11' could not be found.
                  Please use the configure options '--x-includes=DIR'
                  and '--x-libraries=DIR' to specify the X location.
                  See the files 'config.log' and 'ddd/config.log'
                  for further diagnostics.

And here is where I am stuck.  Can anyone tell me why I'm getting this and
how to fix it?

much thanks,
Mike