var banner_height = 0;
var sprite_height = 218;
var banner = null;
var inner = null;

$(document).ready(function() {
    banner = $('div#banner');
    inner = $('<div id="inner_banner"></div>');
    inner.css('opacity', 0);
    banner.append(inner);
    animateBanner();
    
    $('ul.links li a').each(function(){
        $(this).attr('target', '_blank');
    });
});

function animateBanner() {
    setTimeout("switchBanner()", 6000);
}

function switchBanner() {
    if (banner_height == 0){
        var img = new Image();
        img.src = $('div#banner').css('background-image').replace('url("', '').replace('")', '').replace('url(', '').replace(')', '');
        banner_height = img.height;
    }
    if ($(banner).css('background-position') == 'undefined' || $(banner).css('background-position') == null)
        height = $(banner).css('background-position-y');
    else
        height = $(banner).css('background-position').split(' ')[1];
    next = parseInt(height) - sprite_height;
    if (next > (0 - banner_height)){
        inner.css('background-position', 'right ' + next + 'px');
    }
    else {
        inner.css('background-position', 'right 0px');
    }
    inner.animate({opacity: 1}, 1000, resetBanner);
    animateBanner();
}

function resetBanner() {
    if ($(inner).css('background-position') == 'undefined' || $(inner).css('background-position') == null)
        banner.css('background-position-y', inner.css('background-position-y'));
    else
        banner.css('background-position', inner.css('background-position'));
    inner.css('opacity', 0);
}