PageRequestManager

var prm = Sys.WebForms.PageRequestManager.getInstance();

prm.add_pageLoaded(PageLoadedEventHandler);

function PageLoadedEventHandler()

{

alert("Inside PageLoadedEventHandler Working");

}

Sys.WebForms.PageRequestManager.getInstance().add_initializeRequest(InitializeRequest);

function InitializeRequest()

{

alert('Initial requets inside...');

}

By this way, we can fire all the Five ajax page life cycle events.