Closing radwindow after server side code has executed within RadWindow.

Simple way to force closing rad window, just put it inside update panel like that :
<asp:UpdatePanel ID="uppChangeHallPriceWindow" runat="server" UpdateMode="Conditional" RenderMode="Block">
  <ContentTemplate>
     <telerik:RadWindow ID="RadWindow1" runat="server">
       <ContentTemplate>
                                        
       </ContentTemplate>
    </telerik:RadWindow>
  </ContentTemplate>
</asp:UpdatePanel>
Important: you have to apply this properties to the update panel :
 UpdateMode="Conditional" RenderMode="Block"

then inside the button you want to execute the close command perform :
updatepanel1.update()
this command will close radwindow and no refresh to your Webpage and no need to javascript, I tried it.