public void AuthorizeUser(DialogViewController parent, NSAction callback)
        {
            //NSString * OAuthURLString = [kGowallaOAuthURL stringByAppendingFormat:@"?redirect_uri=%@&client_id=%@&scope=%@", kGowallaRedirectURI, kGowallaAPIKey, @"read-write"];
            var authweb = new GowallaAuthorizationViewController(this, config.OAuthUrl + "?redirect_uri=" + config.Callback + "&client_id=" + config.APIKey + "&scope=read-write", callback);

            parent.PresentModalViewController(authweb, true);
        }
        public void AuthorizeUser(DialogViewController parent, NSAction callback)
        {
            //NSString * OAuthURLString = [kGowallaOAuthURL stringByAppendingFormat:@"?redirect_uri=%@&client_id=%@&scope=%@", kGowallaRedirectURI, kGowallaAPIKey, @"read-write"];
            var authweb = new GowallaAuthorizationViewController (this, config.OAuthUrl + "?redirect_uri=" + config.Callback + "&client_id=" + config.APIKey + "&scope=read-write", callback);

            parent.PresentModalViewController (authweb, true);
        }