"onbeforeunload" not firing on unload

Question

I stuck this in a .js file...

window.onbeforeunload = alert('onbeforeunload');

But it fires when the page is loaded, not when it is unloaded.
Does anyone know why?

Answer 1

You have to wrap it... try this instead:

window.onbeforeunload = function(){alert('onbeforeunload')};