ns in Linux?

[Rafa Berenguer <berenguer@bigfoot.com>]

Hi, everyone:

    I am trying to install the latest release ns-2.1b5 on Caldera Open
Linux.
When I tried to build the tk, I got an error like:

==================================================
./configure

loading cache ./config.cache
...
checking for X... (cached) no
checking for X11 header files... couldn't find any!
checking for X11 libraries... checking for -lXwindow... (cached) no
couldn't find any!  Using -lX11.
checking for -lXbsd... (cached) no
...
creating ./config.status
creating Makefile
creating tkConfig.sh

===========================================
make

cc -c -O  -I. -I./../generic -I./../bitmaps -I/root/ns/tcl8.0/generic
-DHAVE_UNISTD_H=1 -DHAVE_LIMITS_H=1 -DSTDC_HEADERS=1 -DHAVE_SYS_TIME_H=1
-DTIME_WITH_SYS_TIME=1      ./tkAppInit.c
In file included from ./tkAppInit.c:16:
../generic/tk.h:74: X11/Xlib.h: No such file or directory


Could anyone give me some advice on that? Thanks in advance.

Rafael Berenguer