$dbhost = 'localhost';
$dbuser = 'root';
$dbpass = '';
$dbname = 'database';
$appname = "Robin's Nest";
$connection = new mysqli($dbhost, $dbuser, $dbpass, $dbname);

function queryMysql($query)
{
global $connection;
$result = $connection->query($query);
if (!$result) die($connection->error);
return $result;
}

$query = "SELECT `id` FROM `user` WHERE email=$lg_email password=$lg_pass";
queryMysql($query);