function get_xhr() {
    xhr = null;
    if (window.XMLHttpRequest) {
        xhr = new XMLHttpRequest();
        if (xhr.overrideMimeType)
             xhr.overrideMimeType("text/xml");
    } else if (window.ActiveXObject) {
        try {
            xhr = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (e) {
            try {
                xhr = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (e) {
                 window.alert("Votre navigateur ne prend pas en charge l'objet XMLHTTPRequest.");
            }
        }
    }
    return(xhr);
}

function bookmark(title, site) { 
    // Firefox 
    if (window.sidebar)
        window.sidebar.addPanel(title, site, '') 

    // IE 
    else if( window.external)
        window.external.AddFavorite(site, title); 
} 

function lien(site) {
    if (site.substr(0, 7) != 'http://')
        site = 'http://'+site;
    window.open(site, '_blank');
}