I was asked to create an IF function...
it is extremely unlikely that you were asked to create an IF function.
firstly, IF() is not an ACCESS function it is an Excel function. in ACCESS the same thing is achieved with the IIF() function, which already exists and you do not have to create it.
I suspect that you were asked to create an expression, using the IIF() function.
the IIF function takes the form: IIf(this thing is true, do this, otherwise do this)
so in your case we have:
Code:
IIf(IsNull([national product number]), "", [national product number])
many thanks,
Cottonshirt