Control Volume with Keyboard Shortcut in Xfce

Thank you! I would have thought this would be a no-brainer hotkey, but it actually took me some time to figure out how to do it. But the volume up and down hotkeys work perfectly!

The mute (toggle) command isn't working quite right for me (on Xubuntu 14.04). It works to mute, but it won't work to unmute. Oh well, I don't really need that one. Thank you again!