gistfile1.js

    var needToConfirm = false;
    
    $('#experience textarea#experience_body, #new-discussion textarea#discussion_posts_attributes_0_text').bind('keypress', function(){
      $('body').css('background-color', '#f00')
      var needToConfirm = true;
    });
    
    $('input[type="submit"]').bind('click', function(){
      $('body').css('background-color', '#fff')
      var needToConfirm = false;
    });
        
    window.onbeforeunload = confirmExit;
    
    function confirmExit(){
      if (needToConfirm == true){
        return "You haven't submitted your changes, and it looks \n" +
               "like you're trying to browse away from this page. \n" +
               "If you leave this page, your current changes will be lost.";
      }
    }