Test Lua

--[[
Version
  0.03 5/10/2017
Changelog
  0.01 - First Draft
  0.02 - Added Support for Bridge Program
  0.03 - Added Support for Bridge No Side Wall Programs
--]]

local options = {
    "Excavation Program 2017",
    "Tunnel Program 2017",
    "Strip Mining Program 2017",
    "Bridge Program 2017",
    "Bridge Program No Side Walls 2017",
    "Next Page",
    "Multi Build Program 2017",
    "Back Page"
}

local optionSize = 8
local n = 1
local currentPage = 1

local function runOptions()
    if n == 1 then
        shell.run("john-ComputerCraft-Program/Excavation2017")
    elseif n == 2 then
        shell.run("john-ComputerCraft-Program/Tunnel2017")
    elseif n == 3 then
        shell.run("john-ComputerCraft-Program/StripMining2017")
    elseif n == 4 then
        shell.run("john-ComputerCraft-Program/Bridge2017")
    elseif n == 5 then
        shell.run("john-ComputerCraft-Program/BridgeNoWalls2017")
    elseif n == 7 then
        shell.run("john-ComputerCraft-Program/")
    end
end

local function gui()
    while true do
        term.clear()
        term.setCursorPos(1,1)
        for i = 1 , 6 do
            if (i + ((currentPage-1) * 6)) <= optionSize then
                if n == i + ((currentPage-1)*6) then
                    print("---> ".. options[i + ((currentPage-1)*6)])
                    print("")
                else
                    print("     ".. options[i + ((currentPage-1)*6)])
                    print("")
                end
            end
        end
        local event, key = os.pullEvent("key")
        if key == keys.up and n > 1 + ((currentPage-1)*6) then
            n = n - 1
        elseif key == keys.down and n < 6 + ((currentPage-1)*6) then
            if(n < optionSize) then
                n = n + 1
            end
        elseif key == keys.enter then
            if n == 6 then
                currentPage = 2
                n = 7
            elseif n == 8 then
                currentPage = 1
                n = 6
            else
                break
            end
        end
    end
    runOptions()
end

gui()