Public Class Form1

   
    Dim pDOO As Single
    Dim pDZPO As Single

    Private Sub optBefore1960_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles optBefore1960.CheckedChanged
        pDOO = 0.089
        pDZPO = 0
    End Sub

End Class
Private Sub optAfter1960_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles optAfter1960.CheckedChanged;
    pDOO = 0.067
    pDZPO = 0.022
End Sub
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click;
    DOO.Text = FormatCurrency(pDOO * Val(txtZaplata.Text), 2)
    DZPO.Text = FormatCurrency(pDZO * Val(txtZaplata.Text), 2)
    Zdravno.Text = FormatCurrency(0.032 * Val(txtZaplata.Text, 2)
    Sum.Text = FormatCurrency(Val(DOO.Text) + Val(DZPO.Text) + Val(Zdravno.Text), 2)

End Sub