Excel VBA Worksheet Change Monitoring

Question

I have an excel sheet that should behave a specific way.

For example the cells I11 - I20 are user input cells in the form of a drop down.

For these cells I need to monitor if a user selects a value that is less than the number 900.

If a user selects a number less than 900 for cell I11 for example, I need to set cells K11 formula to = J11.

If a user selects a number greater than 900, then i clear the formula and allow the cell to be user input.

I need to do this for all cells that range from I11-I20.

Here is what i have for one cell, however i get an error that states "Object variable or With block variable not set" and this only allows me to change one row.

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim A As Range
    Set A = Range("I11")
    If Intersect(Target, A) > 900 Then A.Offset(0, 2).Value = ""
    Application.EnableEvents = False
        A.Offset(0, 2).Value = "=J11"
    Application.EnableEvents = True
End Sub

Thank you for any assistance.

Answer 1

Private Sub Worksheet_Change(ByVal Target As Range)
    If Target.Cells.Count = 1 Then
        If Not Intersect(Target, Range("I11:I20")) Is Nothing Then
            Application.EnableEvents = False
                If Target > 900 Then
                    Target.Offset(0, 2).ClearContents
                Else
                    Target.Offset(0, 2).Formula = "=J" & Target.Row
                End If
            Application.EnableEvents = True
        End If
    End If
End Sub