Submit form as soon as text field will get value by scanning bar code using Ruby on Rails 3

I have one doubt.I want when user will scan one bar code its value will fetch to one text field within one form.As soon as the bar code value will display on text-field that form should submit using Rails 3.I am explaining some codes below please help me to make it successfully.

views/homes/index.html.erb

<%= form_for :hcsy,:url => {:action =>'scan_hcsy' } do |f| %>
    <%= f.text_field :reciept,placeholder:"Get your scan code"' %>
    <% end %>

controller/homes_controller.rb

class HomesController < ApplicationController
    def index

    end
    def scan_hcsy

    end
end

Inside scan_hcsy action i will do some back-end application.Here only i need as soon as the text field will have the bar code value this form should submit.Please help me.