Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
Cancel = True
If Target.Column = 3 And IsEmpty(Target) Then Target.Offset(0, -1).Interior.ColorIndex = 4
If Target.Column = 4 And IsEmpty(Target) Then
With Target.Offset(0, -2)
.Interior.ColorIndex = xlNone
.ClearContents
End With
End If
End Sub