Simple IIf statement I cant seem to get working!

[Troy12]

Hi all,



I am a begginer to MS access and i am struggling with my first IIF statement.
What i need to do is compare month by month sales for 2010 and 2011 and insert text to say if the sales are increasing or decreasing for that particular month. I have managed to do that fine for the first 6 months using the below statement.

My IIF Statement
a: IIf([Diff]>0,"decrease","Increase")

My IIF statement is based on the difference column i inserted (see below)
Diff: [Complete payments_Crosstab]![2010]-[Complete payments_Crosstab]![2011]

However, because i do not yet have the sales figures for the last 6 months in 2011 access is reading the value as 0 and showing these values as 'decrease' when really i would like to just leave these cells blank up until the point the information is available.
I think i need a isnull statement within the above iif statement but i am not quite sure.

I would be grateful for some advice as i have spent all morning trying to work this one out. Thanks!

[rpeare]

IIf([Diff]>0,"decrease",iif([Diff] <0,"Increase", iif([Diff] = 0, "No Change", null)))

Try something like this, with nested IIF statements

Basically you are allowing for only two options if the difference is greater than 0 and anything else when really you have 5 options

1. Diff > 0
2. Diff <0
3. Diff = 0
4. Diff is a null value (I don't know what your data looks like but this may be a possibility)