Comparing data fron 2 different tables and returning a yes or no

[kikpef01]

I am trying to compare data from 2 different tables. See example below

Data from Disp table : Drug Name, Ward Name, Issue date

Data from Ward table: Drug Name, Ward Name

Check data from Disp table is same as Ward table using formular

if Disp.Drug Name = Ward.Drug Name and Disp.Ward Name = Ward.Ward Name then "Y" ELSE "N"

The data changes to list only what appears in the Ward table when the formular in included in the report.

I have tried changing the table join between Disp and Ward to left outer join.

Please help