Informix Error 100

-100 ISAM error: duplicate value for a record with unique key.

A row that was to be inserted or updated has a key value that already exists in its index. For C-ISAM programs, a duplicate value was presented in the last call to iswrite, isrewrite, isrewcurr, or isaddindex. Review the program logic and the input data. For SQL products, a duplicate key value was used in the last INSERT or UPDATE.