Token Poken :( I'm stuck with this

Hay all!
I have question-answer base.. like quiz, yeah? yes!
So i need to do this way... my project without registration so this way
i need token..
user can answer on my question only once.. How can i do this? Iand i can
give him link, and link should be like : localhost:3000/token .. he gets
on this link, answer and click go and that's all. If he want to get on
this page once again he will get message something like "Sorry bro you
already passed quiz".

class AnsweController < ApplicationController

  layout "default"

  $all_questions_archive = Question.count('id')
  $all_questions_active =

  def create

  @w1 = rand(9999999)
  @w = Digest::SHA1.hexdigest(@w1.to_s)
  questions = Question.find(:all,:conditions=>"enabled=1")
  questions.each do |question|
            if params["answer_"]
      flash[:error]="Can`t create answer!"
  if !flash[:error]
          redirect_to :action=>"pass"
           return false


  def index
     @questions = Question.find(:all,:conditions=>"enabled=1")


  def pass
  flash[:notice]="<span id='ty'>Thank you for your answers!</span>"
        render :text=>"", :layout=>"ty"

#view => index.html.erb

<% form_tag :action=>"create" do %>
<table border="0" width="900px" align="center"
  <% @questions.each_with_index do |question, index| %>
  <tr style="vertical-align:middle; text-align:left;">
    <td width="400px" colspan="2" style="padding-top:10px;">

<span style="font-size:15px"><%= index+1 %>. <%= question.text
    <%= text_area_tag "answer_#{}",@answers[],
:cols=>"90", :rows=>"4", :class => 'inputBox' %>
  <% end %>
<table border="0" width="900px" align="center" class="table2">
    <td align="right"><%= submit_tag 'Pass survey &rarr;', :class =>
    <%=h @w %>
<% end %>

What did i do wrong? Please help m,e!