Скачивание материала один раз, на куках

link rel="stylesheet" href="/jgrowl/jquery.jgrowl.css" type="text/css" media="screen" />

<script type="text/javascript" src="/jgrowl/jquery.jgrowl.js"></script>

<script type="text/javascript">  
   
  function createCookie(name, value, days) {  
  if (days) {  
  var date = new Date();  
  date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));  
  var expires = "; expires=" + date.toGMTString();  
  }  
  else var expires = "";  
  document.cookie = name + "=" + value + expires + "; path=/";  
  }  
  function readCookie(name) {  
  var nameEQ = name + "=";  
  var ca = document.cookie.split(';');  
  for (var i = 0; i < ca.length; i++) {  
  var c = ca[i];  
  while (c.charAt(0) == ' ') c = c.substring(1, c.length);  
  if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);  
  }  
  return null;  
  }  
  var userclick=readCookie("userclick");  
  var user='userclick'  
if (userclick== null)  
  {  
  $.jGrowl('<div style="padding:19px 0 0 8px;line-height:1.5;"><b>$USERNAME$</b> Вам необходимо  
<a href="" onClick="createCookie(user, 1, 30);" >скачать</a> фаил</div>', { sticky: true, position: 'center-center', theme:'unice_theme' });  
  };  
  </script>

$.jGrowl('<div style="padding:19px 0 0 8px;line-height:1.5;"><b>$USERNAME$</b> Вам необходимо  
<a href="" onClick="createCookie(user, 1, 30);" >скачать</a> фаил</div>', { sticky: true, position: 'center-center', theme:'unice_theme' });