Authentication Failure when writing a POST manually

[BonAmi]

I want to automate the login process to my router.

So I construct a POST with following data, but get a 200 with authentication failure reply. (Are there mandatory headers to this POST?) Thanks a lot

username:...
password:...
buttonClicked:4
err_flag:0
err_msg:
info_flag:0
info_msg:
redirect_url:
network_name:Guest Network

[Alexander Stevenson]

We'll need more information.  Which router specifically you are using? Can you show us the request and response bodies, please?