CmisSync.SetupController.CheckAddPage C# (CSharp) Method

        public string CheckAddPage(string address)
        {
            address = address.Trim();


            bool emptyAddress = string.IsNullOrEmpty(address);
            bool validAddress = false;
            
            // Check address validity.
            if (!emptyAddress && CmisSync.Lib.Utils.IsvalidURL(address))
            {
                validAddress = true;
                try
                {
                    this.saved_address = new Uri(address);
                }
                catch (Exception ex)
                {
                    Logger.Debug("Error creating URI: " + ex.Message, ex);
                }
            }
            // Enable button to next step.
            UpdateAddProjectButtonEvent(validAddress);

            // Return validity error, or empty string if valid.
            if (emptyAddress)
            {
                return "EmptyURLNotAllowed";
            }
            if (!validAddress)
            {
                return "InvalidURL";
            }
            return String.Empty;
        }

 void CheckAddressTextField()
 {
     InvokeOnMainThread(delegate
     {
         string error = Controller.CheckAddPage(AddressTextField.StringValue);
         if (String.IsNullOrEmpty(error))
         {
             AddressHelpLabel.StringValue = "";
         }
         else
         {
             AddressHelpLabel.StringValue = Properties_Resources.ResourceManager.GetString(error, CultureInfo.CurrentCulture);
         }
     });
 }