public string Hash(Resource resource)
        {
            //encrypt login and password
            string loginName = "";
            string pass = "";
            getloginAndPass(UserId, ref loginName, ref pass);
            string _url = getWSUrl(this.Url);

            RepositoryWebservice repo = new RepositoryWebservice(_url);
            repo.Credentials = new System.Net.NetworkCredential(loginName, pass);

            //just a stub to pass to the service so we pass as little information as possible
            Resource r = new Resource();
            r.ExtractToPath = resource.ExtractToPath;
            r.TemporaryStoragePath = resource.TemporaryStoragePath;

            string hash = repo.GetResourceHash(this.SessionKey, r, loginName, pass); // repo.get .Exists(itemId, loginName, pass);
            repo.Dispose();

            return hash;
        }