What seems to be a problem?

>
>public dbf_sum,balance
>
>Table1's field DR_Amount has following values
>
>24900
>70200
>71500
>
>the value of dbf_sum is =166600 && sum of dr_amount field
>
>the value of BALANCE is =157360 && a supposed variable value
>
>I want to Change dbf field values as
>
>15660
>70200
>71500
>
>Now the sum of dr_amount field is equal to m.balance=157360
>
>Method
>
>If the value of dbf_sum is greater than balance value then the differance must be adjsted in first value
>
>Please help