recordset.cancelUpdate inserts new record

Hi.
Im having problems when calling the cancelupdate of ado datacontrol. heres what im doing. I call the addnew button and then after the user enters the values for each field. calling canceludpate generates an error . It says "The changes to the table you requested were not successful because they would create duplicate values....etc."

I check the database after calling the cancel update. i can see that it inserts records even if i call cancelupdate

I need help asap
:mad: