[ns] Problem with the installation of "ns-allinone-2_1b6a"

[Leyerer Siegfried]

Hi!

After unpacking "ns-allinone-2_1b6a_tar.tar" I tried "./install" to install
the whole package but I always get the same Error:

In file Included from ./tkAppInit.c:16:
../generic/tk.h:77: X11/Xlib.h: File or directory not found
make: *** [tkAppInit.o] Error 1

Does anybody know what I can do in this case???

Thanks

Siegi