function createCookie(name,value,days) {
    if (days) {
        var date = new Date();
        date.setTime(date.getTime()+(days*24*60*60*1000));
        var expires = "; expires="+date.toGMTString();
    }
    else var expires = "";
    document.cookie = name+"="+value+expires+"; path=/";
}
function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for (var i=0; i < ca.length; i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}

function eraseCookie(name) {
    createCookie(name,"",-1);
}
function checkOrCreateAlbum() {
    // check for existing antietam.com photo album
    if (!readCookie('user_album')) {
        FB.api('/me/albums', function (response) {
            var found = false;
            for (r in response.data) {
                if (response.data[r].name == 'My Antietam.com Photos') {
                    createCookie('user_album', response.data[r].id, 31);
                    found = true;
                    window.location.reload();
                    break;
                }
            }
            if (!found) {
                // no album exists, create one.
                FB.api('/me/albums',
                    'post',
                    { 'name': 'My Antietam.com Photos', 'description': 'My photos on Antietam.com' },
                    function (response) {
                        if (!response || response.error) {
                            alert('Sorry! There was an error contacting Facebook. Please wait a moment and try again.');
                        } else {
                            createCookie('user_album', response.id, 31);
                            window.location = '/photo_instructions.php';
                        }
                    }
                );
            }
        });
    } else {
        window.location.reload();
    }
}