Spreadsheet functions

[Fuzzymath]

I am attempting to do a simply budget for something in coming months using a spreadsheet. However, I have run in to a task I have to manually, and I am looking to see how much of it I can offload to a function.

This is the current layout for the spreadsheet:

The Total Balance in cell B17 is simply subtracting the years credits from the years debits. The savings total in cell B18 is just "=D15".

Currently I manually subtract from savings, and make a deduction in the savings column for my changes. What I would like to to do is find a way to do this (--or at least part of it) with the use of a function. I have looked at SUMIF, but I am unable to get it to working correctly. The main problem is that the function wants a range of cells for the conditional IF, and is unwilling to focus on just one defined cell. Additionally, my fear my logic is somewhat circular, "If cell B17 is negative, subtract from cell B18 and add to cell B17", and will become the next hurdle I have to deal with when/if I am able to get SUMIF working. I also have no clue on where to go in getting the spreadsheet to add the deduction to the savings column so the totals would automatically update.

In the end I would want to achieve something like this (--which I do now, just manually):

I know this might be something a beyond a simple spreadsheet but I figure it is worth asking. I have seen some impressive things done in the past, and a few years ago I might of even known how to do them! I have just been away from office programs for far to long, and am in need of a little help.

I also know something like this is best handled by accounting/bookkeeping software. The only defense I can offer is that I am very stubborn, I enjoy working with spreadsheets and this is a -very- small/simple budget that does not meet the scale of such software.

Thanks in advance for any advice or suggestions that can be offered.

[HAckEur]

you may want to research Nestled Formulas with multiple "if" conditions, here an example from one of my spreadsheets:

{=SUM(IF(DATA!$C$1:$C$1000=$B6,IF(DATA!$E$1:$E$1000<=$B$16,IF(DATA!$F$1:$F$1000<=$B$17,DATA!$M$1:$M$1000))))}

The above has 3 conditional "if" values to sum 3 different data criteria cells 1 to 1000 such as debit, credit, saving with interest charges, bank charges etc...