Not the correct number of arguments.
IIf(me![Moisture Exceed] >0)then([Quantity] * [Moisture Exceed] /100 * [Unit Price])
or
=IIf(me![Moisture Exceed] >0)then/100 * {Quantity]*[Unit Price])
I have placed these both in the control source of the text box. Is it not suppose to go there? And If...