สอบถามเรื่อง "Mysqli" มัน ERROR ครับ ไป copy เขามานะครับ

<?php
# FileName="Connection_php_mysql.htm"
# Type="MYSQL"
# HTTP="true"

//-- on darkedition 
$hostname_baanploy = "localhost";
$database_baanploy = "hotelx";
$username_baanploy = "root";
$password_baanploy = "1234";
$database_name = "hotelx";


//-- on programmerhero  
/*
$hostname_baanploy = "programmerhero";
$database_baanploy = "hotel";
$username_baanploy = "root";
$password_baanploy = "sa";
$database_name = "hotel";
*/


$baanploy2 = mysqli_connect("localhost", "root", "1234", "hotelx");
/*$baanploy2 = mysqli_connect($hostname_baanploy, $username_baanploy, $password_baanploy, $database_name) or die(mysql_error());*/ 
mysqli_select_db($baanploy2,"hotelx") or die(mysqli_error());
/*mysql_select_db($database_baanploy);*/
mysql_query("set names utf8");
session_start();


?>