How do I insert into two databases at the same time?

using (IDbConnection connection = new SqlConnection(ConnectionString))
{
  connection.Open();
  var transaction = connection.BeginTransaction();
  try
  {
    string sSql1 = "INSERT INTO  [A].dbo.tbl_std  (userid) VALUES ( @USERID ) "
    string sSql2 = "INSERT INTO  [B].dbo.tbl_cust (userid) VALUES ( @USERID ) "
    var command1 = new SqlCommand(sSql1, connection);
    command1.Parameters.Add(new SqlParameter("@USERID", 101));
    var command2 = new SqlCommand(sSql2, connection);
    command2.Parameters.Add(new SqlParameter("@USERID", 101));
    int iRecordsAffected1 = command1.ExecuteNonQuery();
    int iRecordsAffected2 = command2.ExecuteNonQuery();
    //perhaps check that 1 record has been affected each
    transaction.Commit();
  }
  catch (Exception ex)
  {
    Logger.Error(ex);
    transaction.Rollback();
  }
}