POST /.../logon.aspx/logon.aspx HTTP/1.1
Host: ...
User-Agent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Firefox/45.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://..../edgeway/logon.aspx/logon.aspx
Cookie: ASP.NET_SessionId=bj0jla453vjsfj45xexxa5vj
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 262

__EVaENTTARGET=&__EVENTARGUMENT=&__VIEWSTATE=%2FwEPDwUKMTU3MzM1NjA4NWRkGGSZTNODHD%2B3Qp5GCuONqjdfwdE%3D&__EVENTVALIDATION=%2FwEWBgLc1NytDgKl1bK4CQK1qbSRCwKM54rGBgK7q7GGCALM9PumD%2BJyw5V3YzBaOEAg2ZcdrYjTZBk9&txtUsername=test123&txtPassword=pass123&Button1=+++OK+++