// on collecte les informations sur la résolution de l'écran
function get_screen()
{
    document.ssgg_connexion.res_x.value = screen.width;
    document.ssgg_connexion.res_y.value = screen.height;
    document.ssgg_connexion.win_x.value = window.innerWidth;
    document.ssgg_connexion.win_y.value = window.innerHeight;
    document.ssgg_connexion.depth.value = screen.colorDepth;

    // on test les cas particuliers
    if(document.ssgg_connexion.depth.value == '')
        document.ssgg_connexion.depth.value = screen.pixelDepth;
        
    if(document.ssgg_connexion.win_x.value.toString() == 'undefined')
        document.ssgg_connexion.win_x.value = document.body.clientWidth;

    if(document.ssgg_connexion.win_y.value.toString() == 'undefined')
        document.ssgg_connexion.win_y.value = document.body.clientHeight;
}