private void button6_Click(object sender, EventArgs e)
{
double valorCierreCDT = inversion.cerrar(Int32.Parse(txtmes.Text));
corriente.consignarMonto(valorCierreCDT);
txtcdt.Text = Convert.ToString(inversion.calcularValorPresente(0)) + " [" + Convert.ToString(inversion.darInteresMensual()) + "%]";
txtcorriente.Text = Convert.ToString(corriente.darSaldo());
}