function table_count(tt, item)
  local count
  count = 0
  for ii,xx in pairs(tt) do
    if item == xx then count = count + 1 end
  end
  return count
end

function table_unique(tt)
	local newtable = {}
	for ii,xx in ipairs(tt) do
		if table_count(newtable, xx) == 0 then
			newtable[#newtable+1] = xx
		end
	end
	return newtable
end