MySqlConnection conn = new MySqlConnection();

try
{
     conn.ConnectionString = cs;
     conn.Open();
     MySqlCommand cmd = new MySqlCommand();
     cmd.Connection = conn;

     cmd.CommandText = "INSERT `prueba`.`facturas`";
     cmd.CommandType = CommandType.StoredProcedure;

}
catch (MySqlException ex)
{
     MessageBox.Show("Error: {0}", ex.ToString());
}
finally
{
     if (conn != null)
     {
          conn.Close();
     }
}