mysql_rollback() not working

I had asked this question in another words in my last post and I didn't get the specific answer. So I rephrase. the rollback in the following code is not working. can you please tell me what is wrong:

//Creating and populating a table

C_P_table()
{
    MYSQL *conn;

      conn = mysql_init(NULL);
      if (mysql_real_connect(conn, "localhost", "root",
                "password", "testdb", 0, NULL, 0) == NULL) {
            printf("Error2 %u: %s\n", mysql_errno(conn), mysql_error(conn));
            exit(1);
        }


      if (mysql_query(conn, "CREATE TABLE writers(name VARCHAR(25))")) {
            printf("Error3 %u: %s\n", mysql_errno(conn), mysql_error(conn));

        }
      mysql_autocommit(conn,0);
      if (mysql_query(conn,"START TRANSACTION")) {
                printf("Error4 %u: %s\n", mysql_errno(conn), mysql_error(conn));
      }
      mysql_query(conn,"START TRANSACTION");
      mysql_query(conn, "INSERT INTO writers VALUES('Leo Tolstoy')");
      mysq开发者_StackOverflowl_query(conn, "INSERT INTO writers VALUES('Jack London')");
      mysql_query(conn, "INSERT INTO writers VALUES('Honore de Balzac')");
      mysql_query(conn, "INSERT INTO writers VALUES('Lion Feuchtwanger')");
      mysql_query(conn, "INSERT INTO writers VALUES('Emile Zola')");

      if(!mysql_rollback(conn))
          printf("Roll Back successful\n");
//    mysql_query(conn,"ROLLBACK"); //doesn't work neither

      mysql_close(conn);

}

int main(int argc, char **argv)
{
    C_P_table();
}

My guess is that you are using MyISAM tables, normaly the default table type in MySQL.

So change the line

if (mysql_query(conn, "CREATE TABLE writers(name VARCHAR(25))"))

to

if (mysql_query(conn, "CREATE TABLE writers(name VARCHAR(25)) ENGINE = INNODB"))

and see whats happening.

See: http://dev.mysql.com/doc/refman/5.0/en/storage-engines.html