$db_host = 'localhost';
$db_user = 'your_user_name';
$db_password = 'your_password';
$db_name = 'your_database_name';
$mysqli = new mysqli($db_host, $db_user, $db_password , $db_name);
if ($mysqli->ping())
echo "Server is alive!";
else
echo "Error: ". $mysqli->error;