Что делать?Выдает ошибку

Fatal error: Call to undefined function mysqli_connect() in/home/ecos5x1s/ public_html/conf/dbc.php on line3

<?php

$dbc = mysqli_connect ('localhost', 'ecos5x1s_1', 'пароль', 'ecos5x1s_1') or die ('Ошибка соединения с БД');
mysqli_set_charset($dbc, 'utf8');
?>

<?php
PHPInfo ( ) ;
>

AddDefaultCharset utf-8


RewriteEngine on
RewriteRule ^??$ /start/index.php [L,QSA]
RewriteRule ^login?$ /login.php [L,QSA]
RewriteRule ^reg?$ /reg.php [L,QSA]
RewriteRule ^zona?$ /zona.php [L,QSA]
RewriteRule ^boss?$ /monsters.php [L,QSA]
RewriteRule ^salesman?$ /salesman.php [L,QSA]
RewriteRule ^auction?$ /auction.php [L,QSA]
RewriteRule ^listcompany?$ /listcompany.php [L,QSA]
RewriteRule ^rating?$ /pages/rating.php [L,QSA]
RewriteRule ^help?$ /pages/help.php [L,QSA]
RewriteRule ^masters?$ /masters.php [L,QSA]