Request system: fault at line 68

rednet.open("right")

itemList =
   {
   [1]=
      {
      [1]="Stone",
      [2]="Cobblestone",
      [3]="Dirt",
      [4]="",
      [5]="",
      [6]="",
      [7]="",
      [8]="",
      [9]="",
      [10]="",
      [11]="",
      [12]="",
      [13]="",
      [14]="",
      [15]="",
      [16]="",
      },
   {
   [2]=
      {
      [1]="",
      [2]="",
      [3]="",
      [4]="",
      [5]="",
      [6]="",
      [7]="",
      [8]="",
      [9]="",
      [10]="",
      [11]="",
      [12]="",
      [13]="",
      [14]="",
      [15]="",
      [16]="",
      }
   }
}

while true do

   Object = 0
   Amount = 0
   validObject = false

    while Object == 0 and Amount == 0 do
      print("Input Object: ")
      Object = read()

      print("Input Amount: ")
      Amount = read()

      shell.run('clear')
      sleep(0.1)


      if Object ~= 0 and Amount ~= 0 then

         for i = 1,2 do
            for j = 1,16 do
               if Object == itemList[i][j] then
                  retrieverId = i
                  validObject = true
                  sleep(0.1)
               end
            end
         end
      end

      if validObject == true then
         rednet.send(3, Object)
         sleep(0.2)
         rednet.send(3, Amount)
         print("Request Sent")
      else
         print("Invalid Object")
      end

      sleep(1.5)
      shell.run('clear')


    end
end