/// <summary>
        /// Get counties from web service.
        /// </summary>
        private static void LoadCounties()
        {
            CountyList counties;

            if (Counties.IsNull())
            {
                // Get data from web service.
                counties = new CountyList();
                foreach (WebCounty webCounty in WebServiceClient.GetCounties())
                {
                    counties.Add(new County(webCounty.Id,
                                            webCounty.Name,
                                            webCounty.Identifier,
                                            webCounty.IsNumberSpecified,
                                            webCounty.Number,
                                            webCounty.IsCountyPart,
                                            webCounty.PartOfCountyId));
                }
                Counties = counties;
            }
        }