Html: Background fail - html

Question

I set the body to:
body { background-image: url(file:///Volumes/HDD/photomadness_remixed/css/Flavours_400812054.jp2);
background-attachment: fixed;
background-position: center;
background-size: cover;
z-index: 0;}
and it displays my background but when i set this code:
body {
z-index: -1;
background: #425b77; }
#myBody {
background-image: url(file:///Volumes/HDD/photomadness_remixed/css/Flavours_400812054.jp2);
background-attachment: fixed;
background-position: center;
background-size: cover;
z-index: 0;
}
it just would not display the background and instead just displaying the color i set on the body tag.
Any idea how to solve this?
Edit:
When i look at this code on another webpage i have it works correctly and i have written the exakt same thing.
This is my result from code at the second line:
https://www.dropbox.com/s/ioo1cnfszdzh0wu/Skärmavbild%202014-03-07%20kl.%2018.44.33.png?m=
This is the result i get from the code at line 8 and downwards:
http://www.dropbox.com/s/d8wjnwt346gzdv3/Skärmavbild%202014-03-07%20kl.%2018.44.02.png?m=
Edit:
If i add content inside the <div id="myBody"></div> then it will be blurred too because i want a blur filter on it.

Answer 1

try this :
body {
background: #425b77; }
#myBody {
background:url(your picture) no-repeat center center scroll;
background-size: cover;
-moz-background-size: cover;
width:50%; height:50%;
display:block;
position:fixed;
z-index:1001;
}
this is just example... change position width and height as you wish

Answer 2

You forgot to add Height and Width (or add the content do that div).