How would I take a text box value and use it in the query string on submit? I'd like it to start as this,

/News?favorites=True

and end up something like this after the user enters in a search and clicks search.

/News?query=test&favorites=True

The controller action looks like this

public ActionResult Index(string query,bool favorites)
{
   //search code   
}

This question is something close to what I'd like to do, but I'd like to use the query string and maintain the existing values in the query string.

Thanks.