I have a text box in a data entry form bound to an NON-INDEXED field. I have put in codes to check for duplicates and to prevent input of duplicate data:
If (Eval("DLookup(""[TicketNo]"", ""[TS_Collect]"", ""[TicketNo] = FORM![TicketNo]"") Is Not Null")) Then
Beep
MsgBox "This ticket has been...