function showContent(link) {

        var cont = document.getElementById('contentBody');
        var loading = document.getElementById('loading');

        cont.innerHTML = loading.innerHTML;

        var http = createRequestObject();
        if( http )
        {
            http.open('get', link);
            http.onreadystatechange = function ()
            {
                if(http.readyState == 4)
                {
                    cont.innerHTML = http.responseText;
                }
            }
            http.send(null);
        }
        else
        {
            document.location = link;
        }
    }

    // создание ajax объекта
    function createRequestObject()
    {
        try { return new XMLHttpRequest() }
        catch(e)
        {
            try { return new ActiveXObject('Msxml2.XMLHTTP') }
            catch(e)
            {
                try { return new ActiveXObject('Microsoft.XMLHTTP') }
                catch(e) { return null; }
            }
        }
    }