How to use form_tag with "get" method

I'm trying to use form_tag with get method but it become a post method

<%= form_tag(:method => "get", :room => @room.id) do %>
  <%= label_tag("Vote for:") %>
  ..some thing else..
  <%= submit_tag("Vote") %>
<% end %>

this is my code but if i inspect elemen, it was become :

<form accept-charset="UTF-8" action="/start/testing?method=get&amp;room=43" method="post"><div style="margin:0;padding:0;display:inline"><input name="utf8" type="hidden" value="&#x2713;" /><input name="authenticity_token" type="hidden" value="j4fgdRYJXeyQfmnqMQNFb2fYuw2+/UXRw1UFxc0WuHo=" /></div>
  <label for="Vote_for:">Vote for:</label>
  ..some thing else..
  <input name="commit" type="submit" value="Vote" />
</form>

I think i become a parameter, how can I fix it ? Thank you