I want to execute an action method when the user is abandoning a particular page using jQuery.
The page has the following code:
Actually some browsers such as Google Chrome might block if you attempt to alert in a window unload. As a user I like this feature. Alerting everytime you try to navigate away from a page sucks:

Replace the alert with a console.log or something else less intrusive to the user and the event will be happily called.
You might also want to checkout the onbeforeunload event.