private void ValidateInputNumeric(Object sender,KeyPressEventArgs e)
        {
            TextBox t;
            if (sender.GetType() is TextBox)
            {
                t = (TextBox)sender;
                if (t.Name == txtHarga.Name || t.Name == txtStok.Name)
                {
                    if (!Char.IsNumber(e.KeyChar) && e.KeyChar!=(char)8)
                    {
                        e.Handled = true;
                    }
                }
            }
        }

Private Sub ValidInputNumeric(ByVal sender As Object, _
    ByVal e As KeyPressEventArgs) Handles txtStok.KeyPress, txtHarga.KeyPress
        Dim t As TextBox
        If sender.GetType() Is GetType(TextBox) Then
            t = CType(sender, TextBox)
            If t.Name = txtHarga.Name Or t.Name = txtStok.Name Then
                If Not Char.IsNumber(e.KeyChar) And _
                e.KeyChar <> vbBack Then
                    e.Handled = True
                End If
            End If
        End If
    End Sub