Calculator

term.clear()
term.setCursorPos(1,1)
print"The Calculator Will Produce An Error If You Input A Letter Or Any Character Apart From A Number And A Dot"
sleep(2)
sin = 0
function menu(text, id)
  if sin == id then
        write("[ "..text.." ]")
  else
        write("  "..text.."   ")
  end
  print""
end
term.clear()
term.setCursorPos(1,1)
print"Enter First Number"
write""
input = tonumber(read())
term.clear()
term.setCursorPos(1,1)
print"Select A Symbol"
while true do
term.setCursorPos(1,4)
menu("+ ", 0)
menu("- ", 1)
menu("/ ", 2)
menu("* ", 3)
menu("^ ", 4)
menu("/^", 5)

local event, key = os.pullEvent("key")
if key == 208 then
  if sin > 4 then
        sin = sin - 5
  else
        sin = sin + 1
  end
elseif key == 200 then
  if sin < 1 then
        sin = sin + 5
  else
        sin = sin - 1
  end
elseif key == 28 then
  if sin == 0 then
        term.clear()
        term.setCursorPos(1,1)
        print"Enter Second Number"
        write""
        input2 = tonumber(read())
        output = input2 + input
        term.clear()
        term.setCursorPos(1,1)
        print(output.."         Press Enter To Continue")
        while true do
          event, key = os.pullEvent("key")
          if key == 28 then
            term.clear()
            term.setCursorPos(1,1)
            return
          end
        end
      end
  if sin == 1 then
        term.clear()
        term.setCursorPos(1,1)
        print"Enter Second Number"
        write""
        input2 = tonumber(read())
        output = input - input2
        term.clear()
        term.setCursorPos(1,1)
        print(output.."         Press Enter To Continue")
        while true do
          event, key = os.pullEvent("key")
          if key == 28 then
            term.clear()
            term.setCursorPos(1,1)
            return
          end
        end
      end
  if sin == 2 then
        term.clear()
        term.setCursorPos(1,1)
        print"Enter Second Number"
        write""
        input2 = tonumber(read())
        output = input / input2
        term.clear()
        term.setCursorPos(1,1)
        print(output.."         Press Enter To Continue")
        while true do
          event, key = os.pullEvent("key")
          if key == 28 then
            term.clear()
            term.setCursorPos(1,1)
            return
          end
        end
      end
  if sin == 3 then
        term.clear()
        term.setCursorPos(1,1)
        print"Enter Second Number"
        write""
        input2 = tonumber(read())
        output = input2 * input
        term.clear()
        term.setCursorPos(1,1)
        print(output.."         Press Enter To Continue")
        while true do
          event, key = os.pullEvent("key")
          if key == 28 then
            term.clear()
            term.setCursorPos(1,1)
            return
          end
        end
      end
   if sin == 4 then
     term.clear()
     term.setCursorPos(1,1)
     print("Enter Second Number")
     write""
     input2 = tonumber(read())
     output = input^input2
     term.clear()
     term.setCursorPos(1,1)
     print(output.."           Press Enter To Continue")
     while true do
       event, key = os.pullEvent("key")
       if key == 28 then
         term.clear()
         term.setCursorPos(1,1)
         return
       end
     end
  end
  if sin == 5 then
    term.clear()
    term.setCursorPos(1,1)
    print("Enter Second Number")
    input2 = tonumber(read())
    output = input^(1/input2)
    term.clear()
    term.setCursorPos(1,1)
    print(output.."                      Press Enter To Continue")
    while true do
      event, key = os.pullEvent("key")
      if key == 28 then
        term.clear()
        term.setCursorPos(1,1)
        return
      end
    end
  end

end
end