hide the Progress Indicator for the WebAsyncRefreshPanel and WebTab

Note that since the WebTab and WebAsyncRefreshPanel use the same CallbackManager, a single progress indicator is shared by all WebAsyncRefreshPanels and WebTabs on a page.

Step-By-Step Example

For the WebAsyncRefreshPanel, the following line of JavaScript placed within the client-side InitializePanel event handler will hide the progress indicator.
In Javascript:

oPanel.getProgressIndicator().setTemplate(" ");

For the WebTab, the following line of JavaScript placed within the client-side InitializeTabs event handler will hide the progress indicator.
In Javascript:

oWebTab.getProgressIndicator().setTemplate(" ");