require 'watir-webdriver'
b = Watir::Browser.new :chrome
busy = true
while busy
  puts "sleeping"
  sleep 10
  puts "accessing page"
  b.goto 'http://www.ufrgs.br/ufrgs/aluno'
  puts "filling form"
  form = b.div(:id => 'login').forms.first
  form.text_field(:id => 'cartao').set '171267'
  puts "submitting"
  form.submit
  busy = b.alert.present?
  puts "still busy" if busy
  b.alert.ok if busy
end