trouble with rollovers

hello,
This is my first post, I think I am in the right area. I found some other posts that deal with rollover text but none quite apply to what I am looking to accomplish.

I have a list of four letter codes on sheet one, in sheet two I have a list of what those alpha codes translate into; I am trying to come up with a way that when my cursor is on the alpha code it pops up with the full name.

I have attached a sample of the complete file. any help with this would be very helpful, i don't start with VB prgramming until next semester so please expalin any VB code you might suggest.

thank you,
John