private bool esTarjetaValida()
{
Int64 nroTarjeta;
int vtoMes;
int vtoAnios;
int codSeg;
Int64.TryParse(txtNroTarjeta.Text, out nroTarjeta);
int.TryParse(cboMeses.Text, out vtoMes);
int.TryParse(cboAnios.Text, out vtoAnios);
int.TryParse(txtCodSeg.Text, out codSeg);
SqlCommand command = new SqlCommand();
command.Connection = Program.conexion();
command.CommandType = System.Data.CommandType.Text;
command.CommandText = "SELECT ABSTRACCIONX4.datosValidosDeTarjeta(@tarjNro , @tarjVtoMes, @tarjVtoAnio, @tarjCodSeg, @tarjTipo)";
command.CommandTimeout = 0;
command.Parameters.AddWithValue("@tarjNro", nroTarjeta);
command.Parameters.AddWithValue("@tarjVtoMes", vtoMes);
command.Parameters.AddWithValue("@tarjVtoAnio", vtoAnios);
command.Parameters.AddWithValue("@tarjCodSeg", codSeg);
command.Parameters.AddWithValue("@tarjTipo", cboTipoTarjeta.Text);
return (bool)command.ExecuteScalar();
}