Dear Experts

Table1 has following three fields

grp c(1)
sno n(3)
date d()

Data in table1 is as

A, 5, 01-12-2005
A, 1, 01-12-2005
A, 3, 01-12-2005
B, 2 01-12-2005
B, 4, 01-12-2005

I want to replace sno according to unique grp, in same date, as follows

A, 1, 01-12-2005 && here sno will replace by 1
A, 2, 01-12-2005
A, 3, 01-12-2005
B, 1, 01-12-2005 && here sno will replace by 1 again
B, 2, 01-12-2005

Grp,A,B, means group.
Every new group must start with 1 and should continue increasing by 1 till
end of same date.

There are diffrent dates in table1.

Please help