<!DOCTYPE html>
<style>
#inner {
    position: absolute
}
</style>
<p>You should see the a green 'PASS' below.</p>
<span id="outer">&nbsp;<br>PASS<span id="inner"></span></span>
<script>
window.onload = function() {
    var style = document.getElementById("outer").style;
    document.body.offsetTop;
    style.position = "relative";
    document.body.offsetTop;
    style.color = "green";
}
</script>