I know that this is probably a simple fomula to write, but I'm havingno luck
at all in getting it to do what i want.
Sheet1, col i is a sales figure
Sheet1, col L is a sales date
Sheet2, col C is total monthly sales with the months listed in Col A same
sheet.

I want to automatically add the right sales into the right monthly figures
without having to do it manually, bareing in mind that sheet 1 may not be
entered in a chorological order.
Is this possible and if so, how??