<?php
require ("db_mysql.inc");
// 数据库的运行环境
// (当前仅支持MySQL数据库)
$dbservertype="mysql";

// 服务器的主机名或IP地址
$servername="localhost";

// 登录到数据库的用户名和密码
$dbusername="root";
$dbpassword="";

// 数据库名称
$dbname="forum";

class YZDB extends DB_Sql
{
global $dbname,$servername,$dbusername,$dbpassword;
var $classname="YZDB";
var $Host = "$servername";
var $Database = "$dbname";
var $User = "$dbusername";
var $Password = "$dbpassword";
}
$conDB = new YZDB;
$conDB->connect($Database, $Host, $User , $Password);
?>
高手看看，该怎么改？