question about my expression formatting

[#1]

You guys see anything wrong with this? It's returning no data to display.

sum(if(APEL_LTR_SNT_DT-[Received Date] <= (if(APEL_EXTN_IN = 'N' or isNull(APEL_EXTN_IN), 30,44)) and match(DSFT_SEVY_DS, 'Standard60', '[Moved to Standard30]') and [Medicare Type]= 'C'),1))

I'm wondering if I'm doing the "isNull" wrong?

Maybe it's my entire if, where I'm returning either 30 or 44?

[danielrozental]

isnull is fine, is the value actually null? are you sure it's not blank ('') or something else?

[#3]

Your parens are not matching there... maybe you missed a left paren just before match.

[#4]

Also, in the match(), your 3rd argument is quoted as if you are specifying a string, but you also surround with braces as you would a field.  I don't know your data or intent, but that looks a bit odd.