How to generate the reference number

Hi,

I want to generate a series of number in a Form as reference number
automatically. It likes 0804-0001, 0804-0002,........................ in
each record.

Besides, I also face the problem in printing by using reportview class.
a) sorting by SalesID?

b) I just need to print 1 record information only if sorting by SalesID.
however, it generated all round SalesID started from initially. (such as
record 1,2,3,4,5,.............)

c) How do I make to print 2 copys in 1 record ? (one for customer another
for us)

Anyone help? Thanks