/// <summary>
        /// Enables the DataRepository to programatically create and 
        /// pass in a <c>NetTiersProvider</c> during runtime.
        /// </summary>
        /// <param name="provider">An instatiated NetTiersProvider.</param>
        /// <param name="setAsDefault">ability to set any valid provider as the default provider for the DataRepository.</param>
		public static void LoadProvider(NetTiersProvider provider, bool setAsDefault)
        {
            if (provider == null)
                throw new ArgumentNullException("provider");

            if (_providers == null)
			{
				lock(SyncRoot)
				{
            		if (_providers == null)
						_providers = new NetTiersProviderCollection();
				}
			}
			
            if (_providers[provider.Name] == null)
            {
                lock (_providers.SyncRoot)
                {
                    _providers.Add(provider);
                }
            }

            if (_provider == null || setAsDefault)
            {
                lock (SyncRoot)
                {
                    if(_provider == null || setAsDefault)
                         _provider = provider;
                }
            }
        }
		/// <summary>
	    /// Adds the specified provider.
	    /// </summary>
	    /// <param name="provider">The provider.</param>
	    public void Add(NetTiersProvider provider)
	    {
	        if (provider == null)
	        {
	            throw new ArgumentNullException("provider");
	        }
	        if (!(provider is NetTiersProvider))
	        {
	            throw new ArgumentException("Invalid provider type", "provider");
	        }
	        base.Add(provider);
	    }
		///<summary>
		/// Configuration based provider loading, will load the providers on first call.
		///</summary>
		private static void LoadProviders()
        {
            // Avoid claiming lock if providers are already loaded
            if (_provider == null)
            {
                lock (SyncRoot)
                {
                    // Do this again to make sure _provider is still null
                    if (_provider == null)
                    {
                        // Load registered providers and point _provider to the default provider
                        _providers = new NetTiersProviderCollection();

                        ProvidersHelper.InstantiateProviders(NetTiersSection.Providers, _providers, typeof(NetTiersProvider));
						_provider = _providers[NetTiersSection.DefaultProvider];

                        if (_provider == null)
                        {
                            throw new ProviderException("Unable to load default NetTiersProvider");
                        }
                    }
                }
            }
        }
		/// <summary>
        /// Enables the DataRepository to programatically create and 
        /// pass in a <c>NetTiersProvider</c> during runtime.
        /// </summary>
        /// <param name="provider">An instatiated NetTiersProvider.</param>
        public static void LoadProvider(NetTiersProvider provider)
        {
			LoadProvider(provider, false);
        }
			/// <summary>
			/// Instantiates the configured providers based on the supplied connection string.
			/// </summary>
			private void LoadProviders()
			{
				DataRepository.LoadProviders();

				// Avoid claiming lock if providers are already loaded
				if ( _providers == null )
				{
					lock ( SyncRoot )
					{
						// Do this again to make sure _provider is still null
						if ( _providers == null )
						{
							// apply connection information to each provider
							for ( int i = 0; i < NetTiersSection.Providers.Count; i++ )
							{
								NetTiersSection.Providers[i].Parameters["connectionStringName"] = _connectionStringName;
								// remove previous connection string, if any
								NetTiersSection.Providers[i].Parameters.Remove("connectionString");

								if ( !String.IsNullOrEmpty(_connectionString) )
								{
									NetTiersSection.Providers[i].Parameters["connectionString"] = _connectionString;
								}
							}

							// Load registered providers and point _provider to the default provider
							_providers = new NetTiersProviderCollection();

							ProvidersHelper.InstantiateProviders(NetTiersSection.Providers, _providers, typeof(NetTiersProvider));
							_provider = _providers[NetTiersSection.DefaultProvider];
						}
					}
				}
			}