title: How to Detect Browser Back Button event - Cross Browser
body: <p>How do you definitively detect whether or not the user has pressed the back button in the browser? </p>
  
  <p>How do you enforce the use of an in-page back button inside a single page web application using a <code>#URL</code> system? </p>
  
  <p>Why on earth don't browser back buttons fire their own events!?</p>