os thing

local options = {'Shutdown', 'Reboot'}
local menuopen = false -- variable for checking if the menu is open, to see if we have to draw it

while true do
    -- we're going to draw everything before taking mouse input
    -- clear the screen and prepare for the new screen to be drawn, with the color black
    term.setBackgroundColor(colors.black)
    term.clear()

    -- get the width and height of the screen - is more helpful than memorizing numbers
    -- it also makes it adaptable to other monitor sizes.
    local w,h = term.getSize()

    -- draw a line on the bottom of the taskbar from right to left
    paintutils.drawLine(1, h, w, h, colors.blue)

    -- draw the start button with black text and a lime (light green) background
    term.setTextColor(colors.black)
    term.setBackgroundColor(colors.lime)
    term.setCursorPos(1, h)
    write('Start')

    -- draw the start menu, but ONLY if menuopen is true.
    if menuopen then
        term.setBackgroundColor(colors.white)
        term.setTextColor(colors.black)

        -- a for loop basically says:
        -- repeat the following, starting at 1 and ending at the number of options (2 in this case)
        for i=1, #options do
            -- set our cursor to the left, and a y position based on i
            -- so the first time, it'll be h (51) - 1, or 50
            -- then h - 2, 49
            term.setCursorPos(1, h - i)

            -- print the ith of options
            -- so on the first loop, i will be 1, and this will say print(options[1])
            -- and then options[2]
            print(options[i])
        end
    end

    -- here's where we take mouse input.
    -- use os.pullEvent to get the event pulled, the mouse button pressed, then the mouse x and y
    local event, button, mousex, mousey = os.pullEvent('mouse_click')

    -- check if we're within bounds of the start button
    if mousey == h and mousex >= 1 and mousex <= 5 then
        -- set menuopen to the oppsite of menuopen
        -- so if menuopen is true, menuopen is now false.
        menuopen = not menuopen
    end
end