public static String post(String request) throws Exception {
        if (username == null) {
            username = StoreConfiguration.get("sync_username");
        }
        if (password == null) {
            password = StoreConfiguration.get("sync_password");
        }
        if (syncUrl == null) {
            syncUrl = StoreConfiguration.get("sync_url");
        }

        if (syncUrl == null || username == null || password == null) {
            return null;
        }

        if(debug) {
            System.out.println(request);
        }

        String response = HTTP.post(syncUrl, request, "xml", username, password);

        if(debug) {
            System.out.println(response);
        }

        return response;
    }