Restriction of Duplicate Records

I want to restrict duplicate records in a form from a particular table. Solution required to restrict the duplicate records, other than defining a new key.

Hi, add new field say (FLAG type Boolean), update this field value as true for all duplicate records. Filter the recordset for FLAG = FALSE just before opening the form.

No matter which way you do this, you should probably be defining new keys. Otherwise, you will be doing table scans when you Set the Flag/Filter the Recordset. Another option is to use a temporary table on the form. This would avoid having to update the Flag from above with every insert/modification. It would depend on the table and how many insert/update spots there are.