GTK ./configure problem

["Spooge" <spooge hitter net>]

I have recently downloaded GTK 1.0.6 and uncompressed it and read all the
documentation.  Upon running './configure' I get an error message :

"configure:2014:  X11/Intrinsic.h: No such file or directory
configure: failed program was:
#line 2013 "configure"
#include "confdefs.h"
#include <X11/Intrinsic.h>"

I am running OpenLinux 1.3 and have both X Windows (X11R6) and KDE on it.  I
have
read the FAQ on GTK and browsed the archived messages for the mailing list
to no avail.  Being new to Linux, I'm assuming I'm missing a library?

Thank you for any help anyone can offer me.