javascript - 理解这个返回逻辑

Question

我在一个网站上看到了这个返回代码，我想在我的网站上使用它。我无法理解如何在其中生成 toURl 和 refUrl。请指导一下它们的结构。谢谢

var backtriggered = false;
setTimeout('goBack()',timer);

function goBack() {
  if(backtriggered) return false;
  backtriggered = true;
  toURL=getWelcomeCookie('toURL');
  refURL = getWelcomeCookie('refURL');
  var reg = /(.*)\/sites\/(.*)\/(\d{4})\/(\d{2})\/(\d{2})\/(.*)\/?/;

  if(reg.test(toURL) == false){ 
    document.cookie="toURL"+ "=" +escape(toURL)+";path=/; domain=.mycsnippets.com; expires=Thu, 01-Jan-1900 00:00:01 GMT";
    document.cookie="refURL"+ "=" +escape(toURL)+";path=/; domain=.mycsnippets.com; expires=Thu, 01-Jan-1900 00:00:01 GMT";
 }
  location.href=toURL;
}

Answer 1

document.cookie="toURL"+ "=" +escape(toURL)+";path=/; domain=.mycsnippets.com; expires=Thu, 01-Jan-1900 00:00:01 GMT";

此行将值放入浏览器的 cookie 存储区。有关更多信息，我认为您应该先阅读以下内容:http://en.wikipedia.org/wiki/HTTP_cookie