Hi
you can use the worksheet_change event. Put the following in your
worksheet module:
Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Cells.Count > 1 Then Exit Sub
If Intersect(Target, Me.Range("A1")) Is Nothing Then Exit Sub
On Error GoTo CleanUp:
With Target
If .Value < 5 Then
Application.EnableEvents = False
' insert your code
End If
End With
CleanUp:
Application.EnableEvents = True
End Sub
If using the calculate event, you would also need to consider what happens
after the cell first achieves the tested condition and the macro is run once
for that event.