Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<body>

<div id="test">
<p>Click the button to get the offsetParent for the test div.</p>
<p><button onclick="myFunction()">Try it</button></p>
<p>offsetParent is: <span id="demo"></span></p>
</div>
<script>
function myFunction() {
    var testDiv = document.getElementById("test");
    document.getElementById("demo").innerHTML = testDiv.offsetParent;
}
</script>

</body>
</html>