Code in the app

-- Function that makes a http request to a server and returns false if not succeed, or returns true and the response if  operation was done with success

function getJSONFromServer(serverURL, paramsToBePassed)

    local json = require "json"
    local jsonData = {}
    local linkComplete

    local paramToString = function(paramsTable)
        
        local str = ""
        local i = 1
        
        for paramName,paramValue in pairs(paramsTable) do 
            if i == 1 then
                str = paramName .. "=" .. paramValue
            else
                str = str .. "&" .. paramName .. "=" .. paramValue
            end
            i=i+1
            
        end
        
        return str
        
    end

    local linkComplete = serverURL .. "?" .. paramToString(paramsToBePassed)
        
    -- Makes the request to the server
    local requestResult, requestResultCode = http.request{url = linkComplete, sink = ltn12.sink.table(jsonData), headers = {accept = "application/json"} }
    
    if (requestResult == nil or requestResultCode ~= 200) then  -- Something wrong occurred in trying to download that page, return false
            return false
    else -- download from internet was done with success
        local jsonFree = json.decode(table.concat(jsonData))  -- decodes the JSON data to a table        
            return true, jsonFree
    end
    
end

Code in the server (VB.NET) - filename: getgames.aspx

Partial Class getGames

    Inherits System.Web.UI.Page

   Public Class gameInfoClass
        Public localPlayerID As Integer
        Public opponentPlayerID As Integer
        Public opponentName As String
        Public gameScore As Integer
    End Class

    Public Class OutputClass
        Public status As Boolean
        Public errorMessage As String         
        Public gamesList As New List(Of gameInfoClass)
    End Class


    Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load

        Dim output As New OutputClass

        Dim OKToProceed As Boolean = True

        'Retrieving the GET params
        Dim localPlayerID As String = Page.Request.QueryString("playerID")     
        Dim opponentPlayerID As String = Page.Request.QueryString("opponentID")
      
        'Verifying if required params were entered

        Dim allParamsEntered As Boolean = True

        If localPlayerID = "" Or opponentPlayerID = "" Then

            allParamsEntered = False        

        End If

        If allParamsEntered = False Then
            output.errorMessage = "Required parameters missing"
            OKToProceed = False
        End If

        output.status = OKToProceed

        If OKToProceed = True Then

            ''Opening Connection
            Dim BDConnection = ConfigurationManager.ConnectionStrings("myConnectionString").ConnectionString

            Dim sqlConnection1 As New System.Data.SqlClient.SqlConnection(BDConnection)

            Dim cmd As New System.Data.SqlClient.SqlCommand

            cmd.CommandType = System.Data.CommandType.Text

            cmd.Connection = sqlConnection1

            cmd.CommandText = "SELECT * FROM vw_games WHERE (local_player_id = @localPlayerID and opponet_player_id = @opponentPlayerID)"
            cmd.Parameters.Add(New System.Data.SqlClient.SqlParameter("@localPlayerID", localPlayerID))
            cmd.Parameters.Add(New System.Data.SqlClient.SqlParameter("@opponentPlayerID", opponentPlayerID))

            Try

                sqlConnection1.Open()
                Dim reader As System.Data.SqlClient.SqlDataReader
                reader = cmd.ExecuteReader()
                Do While reader.Read()                    Dim gameInfo As New gameInfoClass
                    
                    gameInfo.localPlayerID = reader("localplayer_id")
                    gameInfo.opponentPlayerID = reader("opponent_id")
                    gameInfo.opponentName = reader("opponent_name")
                    gameInfo.gameScore = reader("game_score")

                    output.gamesList.Add(gameInfo)                     

                Loop

                sqlConnection1.Close()

            Catch ex As Exception

                output.status = False

                output.errorMessage = "Database Error"

            End Try

        End If


        'Writing the output to JSON format
        Dim outputJSON As String
        outputJSON = Newtonsoft.Json.JsonConvert.SerializeObject(output)

        'Printing the JSON in the screen
        Response.Clear()
        Response.Write(outputJSON)
        Response.ContentType = "application/json"
        Response.End()

    End Sub


End Class

local params = {}
params.playerID = "3435434"
params.opponentID = "122343"

local gamesList = getJSONFromServer("http://www.mywebsite.com/getgames.aspx", params)

local linkComplete = serverURL .. "?" .. paramToString(paramsToBePassed)
        
    -- Makes the request to the server
    local requestResult, requestResultCode = http.request{url = linkComplete, sink = ltn12.sink.table(jsonData), headers = {accept = "application/json"} }

local body = paramToString(paramsToBePassed)
    
    local headers = {
        accept = "application/json", 
        ["Content-Type"] = "application/x-www-form-urlencoded",
        ["Content-Length"] = string.len(body),
        ["Accept-Language"] = "en-US"        
        }

    -- Downloading a specific page of popular actors
    local requestResult, requestResultCode = http.request{url = serverURL  sink = ltn12.sink.table(jsonData), method = "POST", headers = headers, source = ltn12.source.string(body) }

      'Retrieving the GET params
        Dim localPlayerID As String = Page.Request.QueryString("playerID")     
        Dim opponentPlayerID As String = Page.Request.QueryString("opponentID")

      'Retrieving the POST params
        Dim localPlayerID As String = Page.Request.Form("playerID")
        Dim opponentPlayerID As String = Page.Request.Form("opponentID")