Update a AjaxPanel from new window postback

Hi all,

I have a AjaxPanel consisting of a radgrid and a button; when I clicked the button, a new RadWindow was opened; on the new opened window, there are a check list and a submit button. Now I want to select items from check list, click submit button to update the AjaxPanel. How could I do this?

So much appriciated for any suggestion.