C# detect postback in webbrowser control
===

I've created an application that grabs data from a web page and saves them to a database. This pages sends some __postbacks. After the postback the page loads some data that I need to save. I do not know how to detect this event so I've created a button which grabs the data when pressed by the user. 
How can I automate the process so that the user won't have to check for the postback himself?
That is how can I detect the postback event in my webbrowser control?