I have just use this method:
and it is working.
but I have another contorl on page like that:
<asp:Button ID="btnRefresh" runat="server" UseSubmitBehavior="false" OnClientClick="disableBtn(this.id)" />
for refreshing the page after the window closed, but the button still been disabled after closing the rad window with 'Esc', but the button work well when closed the window with clicking the close button 'X' on title bar!