TK installation

[ktb <ktb@binary.net>]

    I've never attempted anything like this before so I really have no
clue.  What I'm trying to do is ultimately install the aol instant
messenger program for unix.  To do this I have to install Tcl/Tk.  I
don't know what they are for but I followed the directions and installed
Tcl just fine, I think.  I didn't see any errors and when I type in
"tclsh" at the prompt I get a different prompt "%" and I can type in
commands, so I assume that is Tcl.  Anyway I then tried installing Tk.
I did this first:

~/tk8.0.4/unix$ ./configure -enable-gcc-shared
creating cache ./config.cache
checking for ranlib... ranlib
checking whether cross-compiling... no
checking how to run the C preprocessor... cc -E
checking for unistd.h... yes
checking for limits.h... yes
checking stdlib.h... yes
checking fd_set and sys/select... yes
checking for ANSI C header files... yes
checking for mode_t... yes
checking for pid_t... yes
checking for size_t... yes
checking for uid_t in sys/types.h... yes
checking for sys/time.h... yes
checking whether time.h and sys/time.h may both be included... yes
checking for X... no
checking for X11 header files... couldn't find any!
checking for X11 libraries... checking for -lXwindow... no
couldn't find any!  Using -lX11.
checking for -lXbsd... no
checking for connect... yes
checking for gethostbyname... yes
checking for sin... no
checking for -lieee... no
checking for memmove... yes
checking whether char is unsigned... no
checking for strtod... yes
checking for Solaris 2.4 strtod bug... ok
updating cache ./config.cache
creating ./config.status
creating Makefile
creating tkConfig.sh

And then tried this:

~/tk8.0.4/unix$ make
cc -c -O   -I. -I./../generic -I./../bitmaps
-I/home/kent/tcl8.0.4/generic
-DHAVE_UNISTD_H=1 -DHAVE_LIMITS_H=1 -DSTDC_HEADERS=1 -DHAVE_SYS_TIME_H=1
-D
IME_WITH_SYS_TIME=1      ./tkAppInit.c
In file included from ./tkAppInit.c:16:
../generic/tk.h:77: X11/Xlib.h: No such file or directory
make: *** [tkAppInit.o] Error 1

I'm not sure what this error message means or how to continue with this
installation.  It says something about no X11 file or directory but I
was using X at the time.  I would appreciate it if someone could help me
with this.
Thanks,
Kent