super slider

doing a simple balance sheet(like old bank books). In, out and balance, week by week with formula for calc (eg on cell D5[current balance] put in =SUM(D4+B5)-C5[(previous balance+current week in)-current week out].On cell D6[current balance] put in =SUM(D5+B6)-C6[(previous balance+current week in)-current week out] After putting in each weeks in's and out's i can get the balance to be automatically calculated each week by moving cursor on to previous balance , waiting for the cross to appear and then dragging down. Thats fine but i would like it to automatically fill in the balance when i put in the current weeks values without having to drag the cross down. I can drag the cross down for many rows and it will calculate automatically each time i put in's and out's BUT each row shows the same value until i put in a new weeks in and out. i would like excel to only put a value in when i put a 'in' and/or 'out' for the week i fill in. Just like you would do if you filled in a book yourself. you would only put a new balance in if you put in or took out money
Hoping you understand all this. Its just a simple 3 column formula
Thanks

jods

=IF(B3<>"",C2+A3-B3," ")

So if b3(outgoing) is NOT blank do the sum

super slider

Thanks! Would never have found that