var curThumbId = 1;

function openBigThumb(thumbId)
{
    var url = "http://imagenes.cumlouder.com/" + sceneThumb + "pics/fotos-659x437/foto" + thumbId + ".jpg";
    $("#imgBigThumb").attr("src",url);
    $("#divThumbs").hide();
    $("#divBigThumb").show();
    curThumbId = thumbId;
}

function showThumbs()
{
    $("#divThumbs").show();
    $("#divBigThumb").hide();
}

function nextPhoto()
{
    if (curThumbId <4)
    {
        curThumbId++;
        openBigThumb(curThumbId);
    }
    else
    {
        location.href = $('#natsJoinPage').val();
    }
}