javascript 原生 cookie 处理

function getCookie(name) {
    var start = document.cookie.indexOf(name + "=");
    var len = start + name.length + 1;
    if (( !start ) && ( name != document.cookie.substring(0, name.length) )) {
      return null;
    }
    if (start == -1) return null;
    var end = document.cookie.indexOf(‘;‘, len);
    if (end == -1) end = document.cookie.length;
    return unescape(document.cookie.substring(len, end));
  }

  function setCookie(name, value, expires, path, domain, secure) {
    var today = new Date();
    today.setTime(today.getTime());
    if (expires) {
      expires = expires * 1000 * 60 * 60 * 24;
    }
    var expires_date = new Date(today.getTime() + (expires));
    document.cookie = name + ‘=‘ + escape(value) +
      ( ( expires ) ? ‘;expires=‘ + expires_date.toGMTString() : ‘‘ ) +
      ( ( path ) ? ‘;path=‘ + path : ‘‘ ) +
      ( ( domain ) ? ‘;domain=‘ + domain : ‘‘ ) +
      ( ( secure ) ? ‘;secure‘ : ‘‘ );
  }