// -- Ajax
function GetXmlHttpObject()
{ 
    var objXMLHttp = null;
    if (window.XMLHttpRequest)
    {
        objXMLHttp = new XMLHttpRequest();
    }
    else if (window.ActiveXObject)
    {
        objXMLHttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    return objXMLHttp;
}

// -- popup des images
function OpenImagePopup (Image_Enc, Name_Enc, W, H)
{
    window.open (
            "/show_image.html?P=1&I=" + Image_Enc + "&T=" + Name_Enc,
            "Image" + Math.floor (Math.random() * 1000), 
            "toolbar=0,location=0,top=0,left=0,status=0,menubar=0,scrollbars=0,resizable=0,width=" + W + ",height=" + H);
}