The "public" keyword must all be lowercase letters. The "cid" that you have in admin_motd() is wrong, remove it if you are not using it or fix it if you are going to use it. By fix it, I mean that the proper arguments for a client command are "id, level, cid". To learn how to use these arguments properly, look at other plugins that use them. I'd recommend looking at admincmd.sma.