Duplicate Entries

[DanSMT]

Hi again.

I would like to prevent duplicate entries to be entered into a spreadsheet when attempting to add with a error message saying "Duplicate Entry".

VBA Script below;

Private Sub ScanTB_BeforeUpdate(ByVal Cancel As MSForms.ReturnBoolean)
    Dim LastRowFilled As Long
    Dim DataArray(1 To 4) As String
    Dim i As Integer
    Dim a As Integer, blnFound As Boolean
    Dim strNewName As String
    Dim ws As Worksheet
    Dim boolFound As Boolean
        strNewName = WOTB.Value
    For Each ws In Worksheets
         If ws.Name Like strNewName Then boolFound = True: Exit For
          Next
              If boolFound = True Then
                Sheets(strNewName).Select
                    Else
                       Sheets.Add.Name = strNewName
              End If
                 Cells(1, 5).Select
                 ActiveCell.Value = "=COUNTA((A:A)-1)"
                 Cells(1, 1).Select
                 ActiveCell.Value = "Carton Serial #"
                 Cells(1, 2).Select
                 ActiveCell.Value = "PCB Serial #"
                 Cells(1, 3).Select
                 ActiveCell.Value = "Employee #"
                 Columns("A:B").ColumnWidth = 30
                 Columns("C").ColumnWidth = 11
                 TextBox1.Font.Size = 28
                 TextBox1.Value = ActiveSheet.Range("E1").Value + 1
                    If Me.ScanTB = "" Then
                        Me.ScanTB.SetFocus
                            Else
                                Cells(Rows.Count, 1).End(xlUp).Offset(1).Value = ScanTB.Text
                                Cells(Rows.Count, 2).End(xlUp).Offset(1).Value = Scan2TB.Text
                                Cells(Rows.Count, 3).End(xlUp).Offset(1).Value = EMP.Text
                                Me.Scan2TB = ""
                                Me.ScanTB = ""
                                Cancel = True
                    End If
 End Sub