>I have a database that has 2 tables in a 1-to-many relationship. It is indexed on location. When the user inputs a location, I want to make sure that location is not already in the parent table. Is this possible? I am new to VFP, so the more detailed the better. Thank you in advance.
>Bob Sides.

U have two choices. One check the field at data entry time. The second choice is to check at record save time. I personally prefer at save time from a system performance view point.

Using the valid method below for a LOC_ID field will allow you to check if an entry is already used when U attempt to leave the LOC_ID field. I use SQL over Seeking (which will also work). Make sure U have an index tag on LOC_ID for optimize.

* Location valid
SELECT LOC_ID ;
FROM LOCATION ;
Where LOC_ID = This.value ;
INTO array laTempHold

IF _Tally > 0
* Duplicate Found!
RETURN(.F.)
ELSE
RETURN(.T.)
ENDIF

Well, this is just something quick and very early in the morning. Hope this was Helpful (HtwH). Steve.