Private Sub DataGridView1_MouseUp(ByVal sender As Object, ByVal e As _
   System.Windows.Forms.MouseEventArgs) Handles DataGridView1.MouseUp
'hier ist noch weiterer Code
                        form2.summe = summe
 
  End Sub

 Private loc_summe As Decimal
       Public Property summe() As Decimal
        Get
            Return loc_summe
        End Get
        Set(ByVal value As Decimal)
            loc_summe = value
        End Set
    End Property