function load_banners() {

    var banners = [
        {title: "Интернет-проект по химии", href: '/russian/projects/predmets/chemistry/index.html', bigf: '/images/info/bigf/pr_chem.jpg', bigs: '/images/info/bigs/pr_chem.png', 'small': '/images/info/small/pr_chem.png'},
        {title: "Эколого-биологическая викторина", href: '/russian/projects/predmets/biology/index.html', bigf: '/images/info/bigf/pr_eco.jpg', bigs: '/images/info/bigs/pr_eco.jpg'},
        {title: "Интернет-проект по физике", href: '/russian/projects/predmets/physics/index.html', bigf: '/images/info/bigf/pr_fiz.jpg', bigs: '/images/info/bigs/pr_fiz.jpg'},
        {title: "Олимпиада юных журналистов", href: '/russian/projects/pressman/', bigf: '/images/info/bigf/pr_jur.png', bigs: '/images/info/bigs/pr_jur.jpg'},
        {title: "UNESCO Time Project", href: '/russian/projects/time-2000/index2006.html', bigf: '/images/info/bigf/pr_unesco.png', bigs: '/images/info/bigs/pr_unesco.png'},
        {title: "Посмотри в глаза природе", href: '/russian/projects/nature/index.html', bigs: '/images/info/bigs/pr_nature.jpg', 'small': '/images/info/small/pr_nature.png'},
        {title: "Одаренные дети", href: '/russian/education/deti.html', bigs: '/images/info/bigs/s_deti.png', 'small': '/images/info/small/deti.png'},
        {title: "Программа \"Окно в мир\"", href: '/russian/education/window.html', bigf: '/images/info/bigf/s_window.png', bigs: '/images/info/bigs/s_window.png', 'small': '/images/info/small/window.png'},
        {title: "Академия информационных технологий", href: '/russian/education/ita.html', bigs: '/images/info/bigs/s_academy.png', 'small': '/images/info/small/academy.png'},
        {title: "Банк педагогического опыта", href: '/russian/pedbank/', bigf: '/images/info/bigf/s_bank.png', bigs: '/images/info/bigs/s_bank.png', 'small': '/images/info/small/bank.png'},
        {title: "Форум", href: 'http://forum.edu.yar.ru/', bigs: '/images/info/bigs/s_forum.png', 'small': '/images/info/small/forum.png'},
        {title: "Олимпиада по информатике", href: '/russian/projects/predmets/program/', bigf: '/images/info/bigf/pr_prog.jpg', bigs: '/images/info/bigs/pr_inform.jpg', 'small': '/images/info/small/pr_prog.png'},
        {title: "Образовательный Интернет", href: '/russian/projects/obint/index.html', bigs: '/images/info/bigs/s_obint.png'},
        {title: "Интернет-проект \"Приглашаем в Ярославль\"", href: '/russian/projects/yar1000/index.html', bigf: '/images/info/bigf/yar1000bf.gif', bigs: '/images/info/bigs/yar1000bs.jpg', 'small': '/images/info/small/yar1000s.gif'}
     ];

    makeBanners ('banners', 'image_rnd', banners);
}

function getElementsByClass(searchClass,node,tag) {
    var classElements = new Array();
    if ( node == null )
        node = document;
    if ( tag == null )
        tag = '*';
    var els = node.getElementsByTagName(tag);
    var elsLen = els.length;
    var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
    for (var i = 0, j = 0; i < elsLen; i++) {
        if ( pattern.test(els[i].className) ) {
            classElements[j] = els[i];
            j++;
        }
    }
    return classElements;
}

function getRandomInt(_min, _max) {
    return Math.floor(Math.random() * (_max - _min + 1) + _min);
}

function range (n) {
    var result = new Array (n);
    for (var i = 0; i < n; i++) {
        result [i] = i;
    }    
    return result;
}

function randomBanner (type, banners) {
    var chose = range (banners.length);
    while (chose.length != 0) {
        var rnd = getRandomInt (0, chose.length-1);
        var banner = banners[chose[rnd]];
        if (typeof banner[type] != 'undefined') {
            banners.splice (chose[rnd], 1);
            return banner;
        }
        chose.splice (rnd, 1);
    }
    return false;
}

function makeBanners (root_name, banners_class, banners) {
    var node_list = getElementsByClass ('image_rnd', document.getElementById('banners'), 'a');
    for (var i = 0; i < node_list.length; i++) {
        var node = node_list[i];
        var type = node.getAttribute('type');
        var banner = randomBanner (type, banners);
        if (banner) {
            node.title = banner.title;
            node.href = banner.href;
            var img_list = node.getElementsByTagName('img');
            img_list[0].src = banner[type];
        }
    }   
}