值来自用户登录网站的HTML网络表单。它包含隐藏字段，而不仅仅是用户在屏幕上看到的字段。当Web服务器将HTML传递给浏览器时，这些隐藏字段包含提交回Web服务器的值以及用户键入的值。这就是HTML webforms的一般工作方式。

The values come from the HTML webform that users log in to the site with. It contains hidden fields, not just the fields the user sees onscreen. When the webserver delivers the HTML to the browser, those hidden fields contain the values that get submitted back to the webserver along with the values that the user types in. That is how HTML webforms work in general.