I have table A

ID LASTNAME
1 JOHN
2 MIKE
3 GENE

ID IS Primary key

Table B

ID EID
1 3
2 1

ID and EID in table B are primary keys

tableB.ID is FK references TABLEA.ID

I want my report to display ID AND EID as following:

ID EID
JOHN GENE
MIKE JOHN

I placed ID And EID in detail section, right click ID field =>  Format Field = > Common

placed below formula under Display String

tableA.lastname

I was sucessful to display lastnames since tableA.ID is linked to tableB.ID

I did the same thing with EID, but I was not successful because tableA.ID is not linked to tableB.eid

I even put below formula, still won't work

If tableB.EID = tableA.ID then tableA.lastname

Can you please let me know what to do to display lastname feild from table A when tableB ID = TableB EID?