<!DOCTYPE html>
<html>
<head>
<style>
#myDIV {
    width: 300px;
    height: 300px;
    background: lightblue url('smiley.gif') no-repeat;
    color: white;
    overflow: auto;
}

</style>
</head>
<body>

<p>Click the radio buttons and scroll the DIV element to see the effect of the background-attachment property:</p>

<form name="myForm">
  <input type="radio" name="myAtt" value="scroll" onclick="myFunction()" checked>scroll
  <input type="radio" name="myAtt" value="local" onclick="myFunction()">local
</form>

<div id="myDIV">
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
  <h1>Hello</h1>
</div>

<script>
function myFunction() {
    if (document.forms["myForm"]["myAtt"][0].checked) {
      document.getElementById("myDIV").style.backgroundAttachment = "scroll";
    } else {
      document.getElementById("myDIV").style.backgroundAttachment = "local";
    }
}
</script>

</body>
</html>