I am not sure if these are the right functions for trying to accomplish what i want. I am trying to have a function determine for me the total for each customer.

Ex:
A B
Cust. A 1
Cust. A 2
Cust. A 7
Cust. B 8
Cust. C 1
Cust. C 1
Cust. D 2
Cust. D 2
Cust. D 2
Cust. D 2

Output
Cust. A = 10
Cust. B = 8
Cust. C = 2
Cust. D = 8