اتفضل استخدمت هذا الكود Private Sub Form_BeforeUpdate(Cancel As Integer) Dim sql As String If DCount("[ItemID]", "[InvoiceDetails Table]", "[InvoiceID]=" & Me.InvoiceID & "and [ItemID]=" & Me.ItemID) > 0 Then sql = "UPDATE [InvoiceDetails Table] SET [InvoiceDetails Table].Quantity = [InvoiceDetails Table]![Quantity]+[Forms]![Invoice Table]![InvoiceDetails Table Subform].[Form]![Quantity] WHERE ((([InvoiceDetails Table].InvoiceID)=[Forms]![Invoice Table]![InvoiceDetails Ta