capture user leaving page with jquery

I want to implement a feature that if a user is navigating away from a page and they have unsaved changes on the page they get alerted. So I need to capture the event tha开发者_JAVA百科t fires to movement from the page and perform custom actions on it. Hoping to do this with jquery. Any tips?

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You can't do this with jQuery, but you can attach a handler to window.onbeforeunload with plain JavaScript:

window.onbeforeunload = function() {
  return "You have unsaved changes, do you want to leave?";
};

Just bind this when they make changes to any inputs, and unbind it when hitting the save button (so it won't prompt on submission) with window.onbeforeunload = null;.