I have a annoying problem.
The site is: http://kody.poczta-polska.pl/
What I basically need to do is to fill search box (rounded with red color - http://imgur.com/a/IC1qz ) with some 5 digit number, and press "Szukaj" button (what means in polish 'search').
Here I have fiddler log - https://pastebin.com/J21eXcTc after doing this request manually.
I got from fiddler log two parameters called "kod" = 20-610 and "page" = "kod". I made httprequest and send these parameters, but what I got back is still http://kody.poczta-polska.pl/. So it looks like sending parameters does nothing.
I think there is something with JSON, but I don't know how to make it working. The code I wrote is here: https://pastebin.com/Y5XGnNes
Thank you for any help.