Formula Fields

Hi experts,

i create a crystal reports in that i display item name, description, type, price, qty, total. but i want to display sum of total Type wise in header footer how is it possible. is it possible by Formula? if yes how is it.

Exampole:

name description type price qty Total

a asd A1 20.00 2 40.00

b asdssd A2 50.00 3 150.00

c qee A1 60 5 300.00

Sum of A1 type is 340

Sum of A2 type is 150

How is it possible? i am using CR2008

Regards,

Thippa Reddy