function appel_ajax(fichier){
	if(window.XMLHttpRequest) xhr_object = new XMLHttpRequest();// FIREFOX
    else if(window.ActiveXObject){ // IE
		try {
			xhr_object = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			xhr_object = new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
    else return(false);
    xhr_object.open("GET", fichier, false);
    xhr_object.send(null);
    if(xhr_object.readyState == 4) return(xhr_object.responseText);
    else return(false);
}