[ns] configure failed

["Wayne W. Szeto" <wwszeto@hopper.math.uwaterloo.ca>]

Hi all,
I think this should be a simple problem but I couldn't figure it out.  I
have downloaded ns-2.1b8 and ./configure failed (see below) on the line
where it checks for tclsh8.3, even after I explicitly specify the path of
tclsh8.3 by doing: 
"./configure --with-tk=/fsys/.software/arch@SunOS560-server/tcl-8.3ece"

I have tried specifying the tcl version by doing 
"./configure --with-tcl-ver=8.3" but the same error occured.

The same "type" of error also occur when checking tk -- it said it
couldn't find the file tk.tcl but I have also specified its location (and
it does exist at the specified location).  What could be wrong?? 

P.S. I believe someone else had this problem before on an earlier version,
but I couldn't find the reply/solution for it on the  mailing list
archive.

======
checking for tcl.h... -I/usr/include
checking for libtcl8.3... -R/usr/lib -L/usr/lib -ltcl8.3
checking for init.tcl... no
checking for tclsh8.3.2... no
checking for tclsh8.3... /.software/local/.admin/bins/bin/tclsh8.3
configure: error: Installation of tcl seems incomplete or can't be found
automatically.
Please correct the problem by telling configure where tcl is
using the argument --with-tcl=/path/to/package
======