mysql connect

<?php
$HOST_NAME = "localhost";
$USER_ID   = "";
$USER_PWD  = "";
$DB_NAME   = "";
if(!$db_conn = @mysqli_connect($HOST_NAME, $USER_ID, $USER_PWD, $DB_NAME, 3306)){
	//mysql_select_db($DB_NAME, $db_conn) or die('COULD NOT SELECT DATABASE.');
  echo "mysql not connected ".mysqli_error();
  exit;
}
//mysql_query($connection, "set names utf8");

mysqli_query($db_conn, "set session character_set_connection=utf8;");
mysqli_query($db_conn, "set session character_set_results=utf8;");
mysqli_query($db_conn, "set session character_set_client=utf8;");
?>