Subtract similar data separately in access database using visual Basic 6.0

[Sajjad_1]

i have a program relate to account which subtract value of a Customer but problem is when the user amount is same mean
================  ============


    Customer Name      Amount


================   ==============
John                  200
Max                    100
John                   200


if i input 100
the result will be


    ================  ============
    Customer Name      Amount
    ================   ==============


John                  100
Max                    100
John                   100

but i want the answer


    ================  ============
    Customer Name      Amount
    ================   ==============


John                  100
Max                    100
John                   200

hope you get idea 
if you want then i show my code

Thanks in advance