Script not executing after session timeout with LoadOnDemand and node expanded

[Polaris431]

My treeview is using LoadOnDemand server-side. When my application session times out and the user clicks on a plus sign next to a node to expand the node, the server-side NodeExpand event is fired. At the very start of this event, I create a script and return immediately. The script is suppose to close all open browser windows and redirect the main browser (where the script is executing) back to the login page. The script never gets executed. I have tried using the AjaxManager ResponseScripts.Add method as well as ScriptManager.RegisterStartupScript method but neither works. What do I have to do to get the script executed?