title: Params are empty after form submission
body: <p>I have a from, where users can change their passwords. For now, I haven't done anything about updating the password because my form doesn't pass params for some reason. Before, I give you the code, just to let you know, you will be seeing <code>puts</code> inside command for debugging purposes. </p>
  
  <p>Password Form:</p>
  
  <pre><code>&lt;div class="title"&gt;Change Password&lt;/div&gt;
  &lt;div class="password"&gt;
    &lt;%= profile_error_messages_for(@profile) %&gt;
  
    &lt;%= form_for :user, url: change_password_path do |f| %&gt;
        &lt;%= hidden_field_tag 'attribute', 'password', id: nil %&gt;
        &lt;div class="input-box"&gt;
          &lt;%= label_tag(:current_password, 'Current Password') %&gt;
          &lt;%= f.password_field :current_password, class: 'form-control input-md input-width-large' %&gt;
        &lt;/div&gt;
        &lt;div class="input-box"&gt;
          &lt;%= label_tag(:password, 'New Password') %&gt;
          &lt;%= f.password_field :password, class: 'form-control input-md input-width-large' %&gt;
        &lt;/div&gt;
        &lt;div class="input-box"&gt;
          &lt;%= label_tag(:password_confirmation, 'Password Confirmation') %&gt;
          &lt;%= f.password_field :password_confirmation, class: 'form-control input-md input-width-large' %&gt;
        &lt;/div&gt;
        &lt;%= submit_tag 'Change Password', class: 'btn btn-success btn-md input-width-large' %&gt;
    &lt;% end %&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>profiles_controller:</p>
  
  <pre><code>elsif params[:attribute] == 'password'
    puts 'params: ' + params[:current_password].to_s
  
    puts 'here 1'
    if @profile.password_match?(params[:current_password])
      puts 'here 2'
    else
      puts 'here 3'
      render 'edit'
    end
  end
  </code></pre>
  
  <p>User model:</p>
  
  <pre><code>  def password_match?(entered_password = '')
      puts 'Password: ' + entered_password.to_s
      puts salt
      password == User.hash_with_salt(entered_password, salt)
    end
  </code></pre>
  
  <p>where ever I tried printing out value, it is empty. we don't even need to check model. because when I typed this in controller, it is also empty.</p>
  
  <pre><code>puts 'params: ' + params[:current_password].to_s
  </code></pre>
  
  <p>I have been working on this problem since 3 days. Please somebody help me =). Thank you.</p>