menu = {
    options=nil,
    old_update=nil,
    selected=1,
    return_function=nil,

    show=function(op, retfun)
        menu.options=op
        menu.old_update=update
        update=menu.update
        menu.selected=1
        menu.return_function=retfun
    end,

    update=function()
        --menu.old_update()

        draw.rectf(9,20, 141, 14+#menu.options*10,6)
        draw.rect(9,20, 141, 14+#menu.options*10,8)
        draw.rect(8,19, 143, 16+#menu.options*10,6)

        for i,v in ipairs(menu.options) do
            local color=4
            if menu.selected==i then color=15 draw.text(">",20,20+i*10,color) end
            draw.text(v[1],24,20+i*10,color)
        end
    
        if key.press(key.DOWN) then menu.selected=menu.selected+1 end
        if key.press(key.UP) then menu.selected=menu.selected-1 end
        if menu.selected==0 then menu.selected=#menu.options end
        if menu.selected>#menu.options then menu.selected=1 end
    
        local mx,my=mouse.pos()
        if mx>=20 and mx<=140 and my>=28 and my<=(28+#menu.options*10) then
            menu.selected=math.min(1+math.floor((my-28)/10),#menu.options)
            if mouse.press(mouse.LEFT) then
                update=menu.old_update
                menu.options[menu.selected][2]()
            end
        end

        if key.press(key.RETURN) then
            update=menu.old_update
            menu.options[menu.selected][2]()
        end

        if key.press(key.ESCAPE) then
            if menu.return_function then
                update=menu.old_update
                menu.return_function()
            end
        end

    end
}