Put the following expression in the first blank field in your query:
DueDate:IIF(IsNull(LineDueDate),POHeaderDueDate,Li neDueDate)

Then where you have line due date in your report, change its control source
to DueDate.

Be sure to use YOUR field names in the expression in the query.

Steve



"MNJoe" wrote in message
...
I have a report with GroupHeader0 and GroupHeader1. The data source of the
report is a query. In the GroupHeader0 I have the Purchase Order Header
info
which includes the Purchase Order due date. In the GroupHeader1 I have the
Purchase Order line info which includes the line due date. What I need is
if
the line due date is Null or blank to default to the PO header due date.
How
can I assign the header due date to the line due date. Can I change the
control source of the text box in VB programming.

--
MNJoe