My work is a data base in acess 2000. In a form for a combo box I have set the rule 'No duplicates' to avoid duplicates as the primary field of the form is a differrnt one. However as the form carries many fields after this thers is no warning to know that the field is duplicated until we proceed to the next record after completing the record. This is really ineffecient.
I want to set a validation for this combo box so that as soon as the tab leaves the combo box after selecting a vlaue if the field is duplicated a warning message comes. I tried several validation tricks under validation control of the combo box property settings, but failed.
Please help me.