private string TailleFTPMod(string Nom)
        {
            string Mod = string.Join(",", arrayFileSizeFTPMod.ToArray());
            int nombre = Occurance(Mod, ',');

            string MNom = string.Join(",", arrayFileNameFTPMod.ToArray());
            int Mnombre = Occurance(MNom, ',');

            int i = 1;
            string[] dll = Mod.Split(',');

            return dll[i];
        }
 int Occurance(string chaine, char lettre)
        {
            int nb = 0;
            foreach (char c in chaine)
            {
                if (c == lettre) nb++;
            }
            return nb;
        }