This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
Functions are supposed to be utility kind of code which return some value whereas procedures can have side effects i.e. it changes some value in the database. SP can have IN/OUT parameters which means that more than one return value is possible.