I am just beginning to try using the Athena toolkit and am having some problems 
getting started.  I think that some files are missing on the system, but there is
the possibility that they are just in a different directory.  When I try to link
my program it can't find XtInitailize, XtRealizeWidget, XtMainLoop, 
XtCreateManagedWidget, or commandWidgetClass.  I've included Intrinsic.h and
Command.h.  I also had a problem on compile with XtNcallback but replaced that with
a NULL in order to compile and see if there were any other problems.  I haven't 
used a toolkit before and this is simply an example I got from the manuel.  Can
someone tell me where I might look for these calls, that is, in what file not what
directory they are supposed to be under because the system manager doesn't believe
in standard directories and generally does things his own way.  (I am using UNIX)

Thank you for your assistance.