This is my problem.

I have 2 years.. 2006 and 2007 we will say column A is 2006 and C is
2007. Over in Column D I want to know the actual difference and if it
was greater or less than the previous year. If it was less I want it
to be a negative number. I was thinking it would be a =IF formula but
nothing I do seems to work.

Thank you loads for any help in advance anyone can provide.
Mike