footer.php

<?php

/* 
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

?>

    <!-- jQuery first, then Tether, then Bootstrap JS. -->
    <script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/tether/1.4.0/js/tether.min.js" integrity="sha384-DztdAPBWPRXSA/3eYEEUWrWCy7G5KFbe8fFjk5JAIxUYHKkDx6Qin1DkWx51bBrb" crossorigin="anonymous"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-alpha.6/js/bootstrap.min.js" integrity="sha384-vBWWzlZJ8ea9aCX4pEW3rVHjgjt7zpkNpZk+02D9phzyeVkE+jo0ieGizqPLForn" crossorigin="anonymous"></script>
    
    <script type="text/javascript">
    
    $("#showLogin").click(function(){
        
        $("#signUp").toggleClass("hide");
        $("#logIn").toggleClass("hide");
        if($("#showLogin").html() == 'Login') {
            
            $("#showLogin").html('Sign Up');
            
        } else {
            
           $("#showLogin").html('Login'); 
            
        }
        
    });
    
    $('#diary').on('input propertychange', function() {

        $.ajax({
            method: "POST",
            url: "updateDiary.php",
            data: { content: $("#diary").val() }
        });
    });    

    </script>
    
  </body>
</html>