function getXMLHttpRequest() 
{
    var request = false;
        try {
            request = new ActiveXObject('Msxml2.XMLHTTP');  //internet explorer 6.0 superieur
        }
        catch (err2) {
            try {
                request = new ActiveXObject('Microsoft.XMLHTTP');  //internet explorer 5.0
            }
            catch (err3) {
        try {
            request = new XMLHttpRequest();//mozilla
        }
        catch (err1) 
        {
            request = false;
        }
            }
        }
    return request;
}