I have set the password for root and grant all privileges for root. Why does it say it is denied?

****mysql_query() [function.mysql-query]: Access denied for user 'SYSTEM'@'localhost' (using password: NO) in C:\wamp\www\photo_gallery\includes\database.php  on line 56

Warning: mysql_query() [function.mysql-query]: A link to the server could not be established in C:\wamp\www\photo_gallery\includes\database.php on line 56

The Query has problemAccess denied for user 'SYSTEM'@'localhost' (using password: NO)

Code as follows:

<?php
include("DB_Info.php");

class MySQLDatabase
{
    public $connection;
    function _construct()
    {
        $this->open_connection();
    }
    public function open_connection()
    {   /*
        $DB_SERVER = "localhost";
        $DB_USER = "root";
        $DB_PASS = "";
        $DB_NAME = "photo_gallery";*/
        $this->connection = mysql_connect($DBSERVER,$DBUSER,$DBPASS);
        if(!$this->connection)
        {
            die("Database Connection Failed" . mysql_error());
        }
        else
        {
            $db_select = mysql_select_db($DBNAME,$this->connection);
            if(!$db_select)
            {
                die("Database Selection Failed" . mysql_error());
            }
        }
    }
    function mysql_prep($value)
    {
        if (get_magic_quotes_gpc())
        {
             $value = stripslashes($value);
        }
        // Quote if not a number
        if (!is_numeric($value))
        {
            $value = "'" . mysql_real_escape_string($value) . "'";
        }
        return $value;

    }
    public function close_connection()
    {
        if(isset($this->connection))
        {
            mysql_close($this->connection);
            unset($this->connection);
        }
    }
    public function query($sql)
    {
        //$sql = "SELECT*FROM users where id = 1";
        $result = mysql_query($sql);
        $this->confirm_query($result);

        //$found_user = mysql_fetch_assoc($result);
        //echo $found_user;
        return $found_user;
    }
    private function confirm_query($result)
    {
        if(!$result)
        {
            die("The Query has problem" . mysql_error());
        }
    }

}

$database = new MySQLDatabase();



?>