I am creating an enterprise web template to be used for development of all our web applications. Many of our existing applications take a while to load because of the amount of
With the UpdatePanel, there is an UpdatePanelProgress control to display to the user a progress status message. With JQuery, you can display an element with the please wait message on button click, and attach a generic handler to the ajaxComplete, this callback fires when the AJAX request completes and then you can hide it.
HTH.