Exemple de code de la propriété CSS background-attachment.

<style>body{
 background-image : url(/img/screenshot_css/f_background_attachement.gif); 
 background-repeat : repeat-y; 
 background-attachment : fixed; 
}
#local{
  width:250px; 
  height:150px; 
  border:1px solid #000; 
  overflow : scroll; 
  background-image : url(/img/screenshot_css/f_background_attachement.gif); 
  background-repeat : repeat-y; 
  background-attachment : local; 
}
#local div{
  width:250px; 
  height:350px; 
  overflow : hidden; 
}
</style>
body{ background-attachment : fixed }<br>
identifant{background-attachment:local}
<div id="local"><div>background-attachment:local<br>background-attachment:local<br>background-attachment:local<br>background-attachment:local<br>background-attachment:local<br></div></div>