How to use the BLANK () Function in DAX

Hi Experts! What is wrong with the following DAX Expression... =IF( [UnitPriceDiscountPct] = 0, BLANK () , [UnitPriceDiscountPct] * [SalesAmount] ) It is just a simple example taken from the FactInternetSales table in AdventureworksDW. When I try to add it as a Calculated Column, I got the following... "The syntax for Blank is incorrect...." and so on Anyone who can see the error? Thanks