I created some simple demo code in this forum post
which demonstrates how to do what you are asking. This particular example uses the RadWindow's and RadAjaxManager's client-side API to refresh a FormView control every time the RadWindow is closed. Hopefully this example will get you going in the right direction so that you can successfully implement the feature you are looking for. If you need additional help or have a more specific question, please don't hesitate to ask.