Nga website uses a cookie system that each time you visit a new page or refresh the current one, the cookie changes,which will be used to cross validate with the one on the server. If unmatched, you will be denied access. Fortunately, this cookie is not set in the form of javascript, which otherwise would casuse big headache.
I use this to auto detect key word in the selling information and notify me with email. You need to add your own information before using. Account, password, and reveiver. This is at the end part of secondhand_crawling.py