Shoutbox

I've been trying to figure this thing out, and I'm having the hardest time.  I think I'm going to start using YahooIM if this continues!  Can someone PLEASE help me out?  Most of the stuff I'm seeing in this forum are problems without solutions, or at least quick answers that make no sense.

All I want to do is make it so that when somebody sends me a message, they get an automatic response back, and I can't seem to figure it out.  Someone told me to get the Answering Machine script, but that thing is just as confusing as reading other posts saying that Plus! has an auto-responder already built in, but I can't get that one to work either!

Can someone please tell me what I need to do so that anyone who sends me a message gets an automatic greeting?

Thank you.