[dwm] Multimedia, print screen keys

I've just switched from awesome to dwm, and in the process of migrating
my config from lua to the c header file I've encountered some trouble.

The first problem is I can't get my multimedia keys to function (volume
up/down/mute). I've searched through the mail archives and haven't
found a fix that works for me. In my config.h I've tried to use
XF86AudioRaiseVolume, XK_121 (that's the keycode), and the last thing I
could think of to try was 0x1008ff13 (keysym); but none work.

The next problem I've encountered was the same problem with the print
key. I've tried it's keycode, keysym, and XK_Print, but none of these
work either. I've added #include <X11/keysym.h> to dwm.c, but this
didn't help at all.

Has anyone else achived this sort of thing with just dwm without an
external program like xbindkeys?

I've attached my current config.h also.

Thanks for any help.