config.php

<?php

    if(!isset($dbh)){
        session_start();
        date_default_timezone_set("UTC");
        $musername = "root";
        $mpassword = "";
        $hostname  = "localhost";
        $dbname    = "chatting"; //nama database yang telah dibuat
        $dbh=new PDO('mysql:dbname='.$dbname.';host='.$hostname.";port=3306",$musername, $mpassword);

        include("user_online.php");
    }
?>