function popupA(lien,larg,haut)
{
    if(larg=="" || haut=="")
    {
        larg = "800";
        haut = "600";
    }
    if(larg>screen.width)
    {
        larg = screen.width;
    }
    if(haut>screen.height)
    {
        haut = screen.height;
    }
    var top=(screen.height-haut)/2;
    var left=(screen.width-larg)/2;
    window.open(lien,"","toolbar=0,location=0,directories=0,menuBar=0,scrollbars=1,resizable=1,width="+larg+",height="+haut+",left="+left+",top="+top+"");
}