Hiding A Field

HI,

On a label generated using Crystal, I have added a use by date based on todays date. However if the product id field is blank, then I wish the use by date to also be blank. At the moment I am using an If...Then...Else statement.

I.e.

If ProductID <> "" Then
CurrentDate + 730
Else
CDate(0);

But, this yields the date 30/12/1899 if the productid is blank. Any ideas?

ps I'm using CrystalReports8.5right click on the field and goto suppress ,there write down

is null(Product_ID)

pracalus.