IIF-EEEEE proposition

[Presto731]

I have a query pulling from another that takes into account two columns to arrive at one on the new query.

I need to get my IIf statement working correctly, but cannot seem too. Here's an example

ColumnA is a yes or no answer, if the answer is yes it pulls the data from another column, call it ColumnB. but if the answer is no, then the column should be zero. So if ColumnA=Yes and ColumnB=100, then ColumnC=100, however if ColumnA=NO and ColumnB=100, Then ColumnC should = 0

I got it to work up to this point:

IIf([ColumnA]="yes",[ColumnB]
this part does ok.

What is the second component?

[Stwange]

IIf([ColumnA]="yes",[ColumnB],0) should do the trick