function showGooglemap() {
    var map_object = document.getElementById("googlemap");
    var xhr_object = null;
    var strRetour = null;

    map_object.open;
    map_object.innerHTML = "<img src='images/ajax-loader.gif' alt='image de chargement en cours'>";
    map_object.close;

    if(window.XMLHttpRequest) // Firefox
        xhr_object = new XMLHttpRequest();
     else if(window.ActiveXObject) // Internet Explorer
        xhr_object = new ActiveXObject("Microsoft.XMLHTTP");
     else
     { // XMLHttpRequest non supporté par le navigateur
        strRetour = "Votre navigateur ne supporte pas les objets XMLHTTPRequest...";
    }

    if (xhr_object != null)
    {
        xhr_object.open("GET", "googlemap.php", true);
        xhr_object.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        xhr_object.send(null);
        xhr_object.onreadystatechange = function() {
            if(xhr_object.readyState == 4) {
                map_object.open;
                map_object.innerHTML=xhr_object.responseText;
                map_object.close;
            }
        }
    }
    else
    {
        map_object.open;
        map_object.innerHTML = strRetour;
        map_object.close;
    }

}