Parallax page html and css

So I'm creating a parallax page and i did:

<section class="parallax">
 <div class="parallax-inner">
       <h2>Space</h2>
 </div>

On the css then I put a background and some padding. But here's the problem: I created an h1:

<section class="parallaxtop">
 <div class="parallax-inner-2">
     <h1>Space</h1>     
 </div>

And I set the background bbut it doesn't appear!! I'm 100% sure that i put the right file and the right directory! And I did the same with the h2 div! What should i do?

.parallaxtop{
   background: url("img/pattern.jpg");
}