private void btncolocar_Click(object sender, EventArgs e)
{
double a;
a = Convert.ToDouble(txtcotizacion.Text);
banco x = banco.getInstance();
x.colocarcotizacion(Convert.ToDouble(txtcotizacion.Text));
}
public static banco getInstance()
{
if (instance == null)
{
instance = new banco();
}
return(instance);
}
private void btnobtener_Click(object sender, EventArgs e)
{
banco v = banco.getInstance();
lblcotizacion.Text = v.obtenercotizacion().ToString();
}