Error Compiling for Gnome 2

[Rick Friedman <thelinuxway mailworks org>]

I have Gnome 2 up 7 running thanks to Garnome 0.17.1. However, I have
tried to compile a few other apps and, occasionally, the build bombs out
with the same error:

/usr/bin/ld: cannot find -lSM

It has only been a few apps which do this. What library do I have to get
and where can I get it?

TIA,
Rick