anchor.diff:    User user = (User)session.getAttribute("user");
     if(user==null){
   %>
  +    <td> | </td>
       <td>
         <a href="<%=request.getContextPath()%>/system/register.jsp">Sign up</a>
       </td>
  +    <td> | </td>
       <td>
         <a href="<%=request.getContextPath()%>/system/login.jsp">Sign in</a>
       </td>
  
positive.code: <%
    if(!"true".equals(request.getParameter("index"))){
  %>
      <td>
      <a href="<%=request.getContextPath()%>/index.jsp">Home page</a> <br/>
      </td>
  
negative.code: <script type="text/javascript">
      var contextPath = '<%=request.getServletContext().getContextPath()%>';
  </script>
  <h3>
  <table>
    <tr>
      <td>
        <a href="https://github.com/ysc/superword" target="_blank">View on GitHub</a>
      </td>
        <%--
      <td> | </td>
      <td>
        <div class="bdsharebuttonbox" data-tag="share_1">
          <a class="bds_mshare" data-cmd="mshare"></a>
  