I'm setting up a site, and want to create a responsive background image but I'm getting only single line with background image. What property should i need to use to make the entire background image to fit?

I created 2 files, 
index.html :

```
<div id="logo">Test</div>

```

style.css : 

```
#logo {
background-image: url("bg.png");
background-position: center center;
background-repeat: no-repeat;
background-attachment: fixed;
background-size: cover;
}

```

I tried many times but only single line gets background image. I want the background image to be fully displayed on screen without using height property which i think makes site less responsive.