Prompt when leaving unsaved POST forms

form-saving-prompt.js

$("form[method='post'] :input").change(function() {
	window.onbeforeunload = function(){
		return true; // Prompt if any input has changed
	};
});
$("form[method='post']").submit(function() {
	window.onbeforeunload = null; // Only remove the prompt if it's the submit button
});