cookie|初学 {
  var arg = name + "=";
  var alen = arg.length;
  var clen = document.cookie.length;
  var i = 0;
  while (i < clen) {
    var j = i + alen;
    if (document.cookie.substring(i, j) == arg)
      return getCookieVal (j);
    i = document.cookie.indexOf(" ", i) + 1;
    if (i == 0) break;
  }
  return null;
  }
  function SetCookie (name, value)
  {
  var argv = SetCookie.arguments;
  var argc = SetCookie.arguments.length;
  var expires = (argc > 2) ? argv : null;
  var path = (argc > 3) ? argv : null;
  var domain = (argc > 4) ? argv : null;
  var secure = (argc > 5) ? argv : false;
  document.cookie = name + "=" + escape (value) +
    ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +
    ((path == null) ? "" : ("; path=" + path)) +
    ((domain == null) ? "" : ("; domain=" + domain)) +
    ((secure == true) ? "; secure" : "");
  }
  function setLastlastVisitCookie ()
  {
  var rightNow = new Date();
  var expdate = new Date();
  expdate.setTime (expdate.getTime() + 1 * (24 * 60 * 60 * 1000)); //+1 day
  SetCookie ("lastVisit", rightNow.getTime(), expdate, "/");
  }
  function ResetCookie()
  {
    SetCookie("lastVisit", 0, null, "/");
  }
  // -->