How can I show the orders just for yesterday?

Good afternoon all

I need to produce a report to show just yesterday's orders, this should be dead easy, but I'm finding it harder than I imagined.

The problem I have is to filter the data just so yesterday's appears.

I have tried adding this to my report filter.

1. = If [Posting day] = RelativeDate(CurrentDate() ;1;DayPeriod)  Then 1 Else 0

2. = If [Posting day] = RelativeDate(CurrentDate() ;-1)  Then 1 Else 0

but neither of these work, I just get the choice of either 0 or NULL_VALUE, that is 1 does not appear.

I have also trawled the web but found nothing that helps.

Please assist me if you can, I'd be entirely grateful.

Thanks

Rich