The good news is that you can usually recover your bindings.  To do this, do the following steps:

1. Bring up the "Configure Bindings" form.  Make sure that you have the “Existing Bindings” tab selected.

 2. You may or may not find “City” in the list of Existing Bindings.  If you do see “City”, proceed to step 3.  Otherwise, drag “City” from the “Properties” list on the left side of the form to the list of Existing Bindings.

 

3. Your form should look like this.  Note that for the “City” binding, the Control Type is blank and the Control Name is equal to “[None]”.

4. Click into the Control Name column of City. You should see a drop down list. Pick the appropriate control (in this case "CityTextBox").

 

 

 

5. Once you’ve assigned cityTextBox as the Control Name, your “City” binding should look like this.

 

 

6.Click the OK button to exit the “Configure Bindings” Form.  Build and rerun your application.  Your “City” binding has been restored.