Question about LuaSocket and HTTP

I am trying to learn a bit more about how to download a webpage using LuaSocket. What I was trying to do was download the English Premier league results from

http://www.bbc.co.uk/sport/football/results. . That was easy to achieve with this code

local http = require("socket.http")
local ltn12 = require("ltn12")

    fileHandle = io.open([[c:\_resultsFile.html]], "w")
    url1= [[http://www.bbc.co.uk/sport/football/results]]

   http.request(
       {
           url = "">             sink = ltn12.sink.file(fileHandle),
       })

This is the front page however, what I want to get is all of the Premier league results. I.e manually navigating the webpage I would select "Premier League" from the left most drop down window. I can see from looking at the page source this is achieved by sending a GET string

If I sniff the data actually sent from the webpage when I click on "Premier League", I see

GET /bbc/bbc/s?name=sport.football.results.page&select_change_option_value=competition-118996114&select_change_container=NOT-SET&ns_type=hidden&action_name=select_change&action_type=change&ml_name=webmodule&ml_version=50&app_version=2.7.654&page_type=pal_data&sp=football&bbc_site=sport&pal_route=footballResults&app_type=web&language=en-GB&pal_webapp=sport&prod_name=sport&app_name=sport&blq_s=3.5d&blq_r=3.5&blq_v=default-domestic&blq_e=pal&bbc_mc=ad1ps1pf1&screen_resolution=1324x745&ns_ti=BBC%20Sport%20-%20Football%20-%20Results&ns_c=utf-8&ns__t=1462737017061&ns_jspageurl=http%3A%2F%2Fwww.bbc.co.uk%2Fsport%2Ffootball%2Fresults&ns_referrer=http%3A%2F%2Fwww.bbc.co.uk%2Fsport%2Ffootball%2Ffixtures HTTP/1.1

where the gist of the GET selection for the Premier league appears to be select_change_option_value=competition-118996114

At this point I am stuck, how do I specifiy this GET selection string in the Lua example above ?

Do I add it to the Lua table that is passed to http.request() ? Or more likely do I just append it somehow to the basic site url ?

I have tried numerous variations of adding this to the url but so far cant get it to download the page I want.

Any tips on how to get this http GET to work would be most appreciated. Thanks

Geoff