i have a sheet, which i want to sub total on two levels..

for example, i have a product number, country code, and value. The sheet is sorted by product number then country code.

i require totals for the value of the product (which i can acheive by using the sub total function), but also require a further total for upon change in country code with the the product number :

product number country value
1 a 5
1 a 10
subtotal 15

1 b 15
subtotal 15

Total 1 30

2 c 20
subtotal 20

Total 2 20