alt template background

Hi, I change alt background image, but I can't find any way to cancel background repeating. I want change it to same settings as evo template - fill the page. can somebody help me, thanks 

/path_to_dol/templates/tmpl_alt/css/common.css

body {
    background-image:url(../images/clouds.png);
    background-repeat:repeat;

becomes...

body {
   background-image:url(../images/clouds.png);
   background-repeat:no-repeat;
   background-size:cover;/*this sets the image to fullscreen covering the whole screen*/  
   /*css hack for ie */
   filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='.image.jpg',sizingMethod='scale');
   -ms-filter:"progid:DXImageTransform.Microsoft.AlphaImageLoader(src='image.jpg',sizingMethod='scale')";

Taken from http://stackoverflow.com/questions/10869739/how-to-make-full-screen-backgound-in-a-web-page.
There is something you should bear in mind, the full screen CSS will stretch your image to fit the screen, so if your page is very long, the image will be stretched to fit lengthways which will also stretch the image widthways, and visa versa.
Don't forget to back up the original file in case you want to go back.

thanks, but it not solve my problem ... on some another place must by information about background - for example - in template dir I change clouds.png to cloud.png, same change I make in common.css and after it I have page without background :( not only in common.css is info about background ...

Strange, it worked for my ALT template, using Firefox browser.
Maybe if I saw the page, I could help you further.

my testing page is here

http://marvvin.cz/dolphin/index.php?skin=alt

Did you clear the cache?
administration >> tools >> cache >> clear all.
Your current stylesheet is referencing a file that doesn't exist (clouds.png), when it needs to reference 'cloud.png'.
I find it far better to disable the cache in the administration center when developing.

thanks a lot, cache is my problem :) 

and about long sites - you can use 

background-attachment: fixed;

and picture stay on page and text rolls in the foreground ...