试试这个:  
设置方法:
function setCookie(name, value, days)
{
  var expires;
  if (days)
  {
    var date = new Date();
    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
    expires = "; expires=" + date.toGMTString();
  }
  else
  {
    expires = "";
  }
  document.cookie = name + "=" + value + expires + "; path=/";
};
获取方法:
function getCookie(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;
};
我已经分别更改了 jsfiddle:http: //jsfiddle.net/DVeVm/