Another table occurence?

[DB_Noob]

Hello, I need help.

TABLE with these fields in questions:

_kf_TASK_ID, not unique (related to a TASK table in which the TASK_IDs in that table are unique)

ROUTE_TYPE, not unique, values: "Contract", "In House", "Task Order"

ORIGINAL, not unique, values: "Original", "Amendment"

Basically, when creating a record, I don't want to be able to pick "Amendment" in the ORIGINAL field if there is no existing record that matches the TASK_ID and ROUTE_TYPE that has an "Original" in the ORIGINAL field.

So, I know the script/relationship has to read something like:

search for the current TASK_ID and ROUTE_TYPE in the Table.

IF any of these records have "Original" in the ORIGINAL field, can put anything in the ORIGINAL field.

IF any of these records do not contain "Original" in the ORIGINAL field, IF you pick "Amendment" it is an error.

Thanks!!!