chat_javascript.js

 lastMessageID = 0;

 function getXHR() {
    var xhr = null;

    if (window.XMLHttpRequest || window.ActiveXObject) {
        if (window.ActiveXObject) {
            try {
                xhr = new ActiveXObject("Msxml2.XMLHTTP");
            } catch(e) {
                xhr = new ActiveXObject("Microsoft.XMLHTTP");
            }
        } else {
            xhr = new XMLHttpRequest();
        }
    }

    return xhr;
}

function ajax_req_and_callback(page, callback) {
    var xhr = getXHR();
    xhr.open("GET", page);
    xhr.send(null);
    xhr.onreadystatechange = function() {
        if(xhr.readyState == 4)
            callback(xhr.responseText);
    }
}

function MaJSiNouveauxMessages() {
    ajax_req_and_callback("messages.php?count", function(r) {
        if(r > lastMessageID) {
            ajax_req_and_callback("messages.php?depuis="+lastMessageID, function(a) {
                document.getElementById("messages").innerHTML += a;
            });
            lastMessageID = r;
        }
    });
}


var updateMsgTimer = window.setInterval(MaJSiNouveauxMessages, 1000);