title: How do I add style and html to flash error message in my controller in Rails 4.0
body: <p>I have this in my UserController.rb</p>
  
  <pre><code>           def create
                  @user = User.new(user_params)
                  if @user.save
                      sign_in @user
  
                      flash[:success] = "Welcome to the TurnKii!"
  
                      redirect_to @user
                      # Handle a successful save.
                  else
  
  
                      redirect_to signup_url
                      flash[:error] = @user.errors.empty? ? "Error" :  @user.errors.full_messages.to_sentence
  
                  end
              end
  </code></pre>
  
  <p>the code works right now, but I would like to add some styling to my flash error message, it just shows up on the top of the page as bare text in 1 sentence. </p>
  
  <p>I dont mind the sentence, but I would like to add some styling to this and semantic tags as well. </p>
  
  <p>Currently its showing up on the page inside a </p>
  
  <pre><code> &lt;div class="alert alert-danger"&gt;Error Sentence here&lt;/div&gt;
  </code></pre>
  
  <p>i have tried to style that in my css, but its not rendering. I would like to have something like this(or similar)  for my flash message</p>
  
  <pre><code>                    flash[:error] = @user.errors.empty? ? "Error" :  &lt;h1 class=alert-danger &gt;@user.errors.full_messages.to_sentence&lt;/h1&gt;
  </code></pre>
  
  <p>but anytime i add anything in there, I run into errors. </p>
  
  <p>Can anyone help?</p>