Need help with my OS

w,h = term.getSize()
running = true
timeR = nil
refreshRate = 0.2
isDrawed = false
done = false
items = {
	{
		name="Exit",
		func = function()
		running = false
		shell.run("clear")
		end,
		ypos = 0,
		xpos = 0 -- Changed this
	},
	{
		name="Refresh",
		func = function()
		end,
		ypos = 0,
		xpos = 0 -- Changed this
	}
}

function drawTask()
	term.setCursorPos(1,h-1)
	term.setBackgroundColor(colors.blue)
	term.write(string.rep(" ",w))

	term.setCursorPos(1,h)
	term.write(string.rep(" ",w))

	time = textutils.formatTime(os.time(),true)
	term.setCursorPos(w-string.len(time),h)
	term.write(time)

	term.setCursorPos(1,h-1)
	term.write("+-+")
	term.setCursorPos(1,h)
	term.write("+-+")
	term.setBackgroundColor(colors.black)
end

function onDrawMenu()
	term.setCursorPos(1,h-2-table.getn(items))
	term.setBackgroundColor(colors.gray)
	term.setTextColor(colors.black)
	large = 0
	for i=1,table.getn(items) do
		if string.len(items[i].name) > large then
			large = string.len(items[i].name)
		end
	end
	--[[
		It changes the xpos and ypos for where it actually prints, although
		it changes each time it prints which isn't good practice.
		Make the default value of xpos and ypos in the table to where it must print
		and then use term.setCursorPos(items[i].xpos, items[i].ypos) to set the 
		position it must print
	]]--
	for i=1,table.getn(items) do
		term.setCursorPos(1,h-1-i)
		term.write(string.rep(" ",large))
		term.setCursorPos(1,h-1-i)
		term.write(items[i].name)
		items[i].xpos = 1
		items[i].ypos = h-1-i
	end
	isDrawed = true
	term.setBackgroundColor(colors.black)
	term.setTextColor(colors.white)
end

function updateMouse(button,xpos,ypos)
	if button == 1 then
		if xpos == 1 and isDrawed == false or xpos == 2 and isDrawed == false or xpos == 3 and isDrawed == false then
			if ypos == h-1 or ypos == h then
				onDrawMenu()
			end
		elseif isDrawed then
			done = false
			for j=1, #items do
				if xpos >= items[j].xpos and xpos <= #items[j].name and ypos == items[j].ypos then -- this is the way to do it :D/>
					term.clear()
					items[j].func()
					isDrawed = false
					done = true
					break
				end
			end
			if done == false then
				isDrawed = false
				drawAll()
			end
		end
	end
end

function drawAll()
	shell.run("clear")
	drawTask()
	if isDrawed == true then
	  onDrawMenu()
	end
	term.setCursorPos(1,1)
end

function updateAll()
	e,p1,p2,p3 = os.pullEvent()
	if e == "timer" and p1 == timeR then
		drawTask()
		timeR = os.startTimer(refreshRate)
	elseif e == "mouse_click" then
		updateMouse(p1,p2,p3)
	end
end

timeR = os.startTimer(refreshRate)

while running do
	drawAll()
	updateAll()
end