Logging in successfully redirects back to login page

When I was testing my website on my friends Mac, when logging in, it redirects back to the login page. I asked my friends to test it on their Windows computer and was working fine.

Here's my login page: http://ift.tt/1Ndmun0

Enter the login details:

username: jim

password: Test999$

I have looked into my php code and it looks fine. I was thinking the issue could be coming from $ogMeta where it goes to another page.

Here's my login page code: http://ift.tt/1HBzfco

The login page should go to members page when login is successful, here's a piece of my membersarea.php code:

<?php
session_start();

if (!$_SESSION["myusername"]) {
    $ogmeta = '<meta http-equiv="refresh" content="0;url=http://ift.tt/1Ndmun0">';
    echo $ogmeta;
} else{
    $id = $_SESSION['myid'];
    $user = $_SESSION['myusername'];
    $pass = $_SESSION['mypassword'];
    $email = $_SESSION['myemail'];
}
?>

Any suggestions on what's causing this problem to happen?