My problem is that my formula is returning values for which there shouldn't
be a value. Here's the first formula...

=LOOKUP(A4,'[Sortable Complete Records.xls]Sheet1'!$A$4:$A$1000,'[Sortable
Complete Records.xls]Sheet1'!$B$4:$B$1000)

It returns the proper result.

The next line has this formula...

=LOOKUP(A5,'[Sortable Complete Records.xls]Sheet1'!$A$4:$A$1000,'[Sortable
Complete Records.xls]Sheet1'!$B$4:$B$1000)

There is no match for "A5" in the other spreadsheet, so I'd like it to
ruturn either a "0" or nothing. Instead, it returns the same results as the
previous line.

Thanks in advance for any help.