Updating existing record in database

[spoox2]

I have a field "Quantity"(Its a invoice detail quantity which adds the number of items) in a form which updates a field "total" in a different table (Products table where the totals refers to the hands on quantity.). When i add a new invoice, i am able to handle it. But when i need to change an existing record , i.e update a wrongly entered quantity, i dunno how to handle the updated quantity and update the products total to match the difference between my old value for "Quantity" and the new value. I am new to visual basic. One way i thought was to actually handle the difference by subtracting the old value from the totals in the "Before Update" method and then add the new quantity in the "After Update" method. Please let me know if its the right way to go or is there a better approach. Any help would be appreciated. Thanx.

 

[guitardave78]

that would work quite well actually!