thank you again.........
yes, the key.transfer is storing the staff_id ..I have try left join on
the line that
JOIN staff s2 ON staff.staff_id=key.transfer
and it post out the out records but with the s2.name field= .null.

I did check the dbf file, the transfer field has the id number that exit in the staff.dbf.......I am totally screw up this time....