FB_Decrease Value In Worksheet Change Event

https://excel-egy.com/forum/f33
-------------------------------

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim v As Double, x As Double, c As Long

    If Target.CountLarge > 1 Then Exit Sub

    If Target.Column = 8 Then
        Application.ScreenUpdating = False
            v = Val(Target.Value)
            If v > 0 Then
                For c = 7 To 1 Step -1
                    If v - Cells(Target.Row, c) >= 0 Then
                        v = v - Cells(Target.Row, c)
                        x = x + Cells(Target.Row, c)
                        Cells(Target.Row, c) = 0
                    End If
                    If v = 0 Or c = 1 Then Target.Value = Target.Value - x: Exit For
                Next c
            End If
        Application.ScreenUpdating = True
    End If
End Sub