Miért kapom ezt a hibaüzenetet?

ezzel is hibát kapok:

Warning: mysqli_query() expects parameter 1 to be mysqli, boolean given in C:\wamp\www\asd\dbconn.php on line 10

kód:

$connect=@mysqli_connect($host,$username,$password, $database);

mysqli_query($connect, "SET NAMES UTF8");

<?php

header("Content-Type: text/html; charset=utf-8");

$host="localhost";

$username="username";

$password="password";

$database="database";

$connect=@mysqli_connect($host,$username,$password, $database);

mysqli_set_charset($connect, "utf8");

//mysqli_query($connect, "SET NAMES UTF8");

if(mysqli_connect_errno()) {

echo "Hiba: ".mysqli_connect_error();

exit();

}

date_default_timezone_set("Europe/Budapest");

?>