function getRequestObject() {
    try {
        return new XMLHttpRequest(); /* e.g. Firefox */

    } catch (e) {
        try {
            /* some versions IE */
            return new ActiveXObject("Msxml2.XMLHTTP");

        } catch (e) {
            try {
                /* some versions IE */
                return new ActiveXObject("Microsoft.XMLHTTP");

            } catch (e) {
                return false;
            } 
        } 
    }
}

var xhr = getRequestObject();

xhr.onreadystatechange = function() { 
    if (xhr.readyState  == 4) {
        var div = document.getElementById('news');

        if (xhr.status  == 200)
            div.innerHTML = xhr.responseText;
        // else div.innerHTML = "<b>Error: " + xhr.status + "</b>"
    }
};

xhr.open('GET', sidebar_url, true);
xhr.send(null);