Public Sub SumSelected(ByVal prm As Boolean)
    Dim rs As Recordset, i As Integer, ss As Currency, fltop As Boolean
    On Error GoTo sum_selected_err
    SaveChange Me.ActiveControl, Screen.ActiveForm
    ss =  0 
    If Me!list.Form.SelHeight <>  0  Then
        Set rs = Me!list.Form.RecordsetClone
        rs.Bookmark = Me!list.Form.Bookmark
        fltop = (Me!list.Form.SelTop -  1  = rs.AbsolutePosition)
        i =  0 
        Do
            ss = ss + Nz(rs!sm,  0 )
            i = i +  1 
            If i < Me!list.Form.SelHeight Then
                If fltop Then
                    rs.MoveNext
                Else
                    rs.MovePrevious
                End If
            End If
        Loop Until i = Me!list.Form.SelHeight
        rs.Close
        MsgBox "Сумма . . . . . . . " & Format(ss, "# ##0.00")
    Else
        Beep
    End If
    Exit Sub
sum_selected_err:
    show_error
End Sub