if doesn't work, what am I doing wrong?

Question

Ruby on Rails

Hello.
There is a helper

module ArticlesHelper
  def image_from_amazon(amazon_id)
    	image_tag "http://images.amazon.com/images/P/#{amazon_id}.01.ZTZZZZZZ.jpg"
  end
end

I try like this

module ArticlesHelper
  def image_from_amazon(amazon_id)
    if amazon_id == nil
      image_tag "http://vk.com/images/deactivated_100.png"
    else
    		image_tag "http://images.amazon.com/images/P/#{amazon_id}.01.ZTZZZZZZ.jpg"
    	end
  end
end

As a result, the picture is not placed, but on the page it displays

<img src="http://images.amazon.com/images/P/.01.ZTZZZZZZ.jpg" alt=".01.ztzzzzzz">

Answer 1

Are you sure amazon_id is nil?
==''

Answer 2

If you are using Rails, then it is amazon_id == nilwiser to use amazon_id.blank?