This is Relationships.
Can anybody reply me? Any hint plz?
on which of these three tables is your layout based?
Do you have a field for identifying each salesman?
"Sale Sheet" is based on "tblSale". Each salesman is identified in "tblSmNames". All + - are in "tblBalance". And In "LaySale Sheet" the field "Name" is a dropdown list (Two fields tblBalance: :tblSmNamesIdFk and tblSmNames: :Name)
Select Balance while in the window shown in your screen shot and then click the duplicate button (two green plus signs) to make a duplicate table occurrence.
Link it to Balance like this: (You can double click the new table occurrence to open a dialog where you can rename it as I have done here.)
Balance::SmNamesIDFk = Balance|SameSalesMan::SmNamesIDFk AND
Balance::Date > Balance|SameSalesMan::Date
Double click the relstionship line and specify a sort order for Balance|SameSalesMan that sorts the related records in descending order by Date. This makes the next oldest record for this salesman the first related record when you use this new relationship.
You can then set up a field in Balance that uses a looked up value setting to auto-enter the desired value from Balance|SameSalesMan to use as the preceding balance in your calculations.