function A_retrieve(ajaxfile, infos, asynch) {
    if ((asynch == "") || (asynch == null))
	asynch = false;
    var xhr_object = null;
    if(window.XMLHttpRequest) // Firefox
        xhr_object = new XMLHttpRequest();
    else if(window.ActiveXObject) // Internet Explorer
        xhr_object = new ActiveXObject("Microsoft.XMLHTTP");
    else { // XMLHttpRequest non support? par le navigateur
	alert("Votre navigateur ne supporte pas les objets XMLHTTPRequest...");
	return false;
    }
    data_url = ajaxfile; // Le lien relatif vers le php
    xhr_object.open("POST", data_url, asynch);
    xhr_object.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    if (infos == "") {
	xhr_object.send(null);
    } else {
	xhr_object.send(infos);
    }
    if (xhr_object.readyState == 4) {
        return xhr_object.responseText;
    }
}