I am trying to compare two text fields txtTrailerNumber and txtSealNumber to the database table Tab_TrailerDetails. [TrailerNumber] and [SealNumber] as listed in the table.
I am trying to get the database to look at the trailer number entered into the form, and if it finds a duplicate value it then looks at the seal number entered into the form. If both values have a duplicate found in the table it should throw up the Msg_Box error code.
Private Sub txtSealNumber_AfterUpdate() Dim NewTrailer, NewSeal As String Dim stLinkCriteria As String 'Assign the entered Trailer Number and Seal Number to a variable NewTrailer = Me.txtTrailerNumber.Value NewSeal = Me.txtSealNumber.Value stLinkCriteria = ("[TrailerNumber]='" & NewTrailer & "'" And "[SealNumber]='" & NewSeal & "'") If Me.txtTrailerNumber = DLookup("[TrailerNumber]", "Tab_TrailerDetails", stLinkCriteria) Then MsgBox "This trailer, " & NewTrailer & ", has already been entered in database," _ & vbCr & vbCr & "along with seal " & NewSeal & "" _ & vbCr & vbCr & "Please make sure Trailer and Seal are not already entered.", vbInformation, "Duplicate information" 'undo the process and clear all fields Me.Undo End If End Sub