However, I'm getting an error -  In Criteria left expression is of type STRING and right expression is of type BIGINT and the operator == is not valid

Here is what I have build.  3 Forms

Leases

      - Lease Name

Tanks (multiple tanks per lease)

      + Lookup Lease Name

      - Tank ID

Gauge Form

      +  Lookup Lease Name

      +  Lookup Tank (only want to display tank records associated with the lease from the previous lookup value)

Thanks,

Chris