How to load the the updated content to do some processing.

How to load the the updated HTML content to do some processing using webbrowser control.I am using a webbrowser control in my app to load a page that update its contents dynamically via ajax.I need to access the dynamic content to do some processing,but since the calls are made with ajax the page does not get refreshed and thus the documentcomplete event doesnot fire.Is there a way to get a notified when a call is using the xmlhttprequest object?some event fires may be?Any help will be greatly appreciated..