background-attachment
Syntax:

background-attachment: scroll | fixed


<style type="text/css">
.demo1 {
   background-image: url("../images/logo.gif");
   background-repeat: no-repeat;
   background-attachment: fixed;
   width: 200px;
   border: 1px solid;
   height: 400px;
}
</style>
<div class="demo1"></div>
<style type="text/css">
.demo2 {
   background-image: url("../images/logo.gif");
   background-repeat: no-repeat;
   background-attachment: scroll;
   width: 200px;
   border: 1px solid;
   height: 500px;
}
</style>
<div class="demo2"></div>