Programming, Missing XMstrings

I was using Rupert Post " Programming challenge: Create a GUI window" to help learn a little about how a GUI window is built. I used the code that Rupert posted in his opening of the thread.
when I use code blocks to compile the code I get 40 errors the all have to do with the "XMStrings" So I set out to try to fix this.

What I have tried so fare
(yum install openmotif-devel) no change to errors
Searched yum for Motif installed Motif and Motif-devel no change to errors
Searched yum for Motif uninstalled Motif and Motif-devel and installed Lesstif and lesstif-devel
and I get only one error when compiling missing #include <Xm/Xm.h> no such directory

Does any one know of a terminal code to install motif that isn't already listed in
YUM EXTENDER ?
VR
Seth