My JavaScript code won't work on FireFox
<pre><code>&lt;script&gt;
window.onscroll = function (oEvent) {
    var mydivpos = document.getElementById("about").offsetTop;
    var scrollPos = document.getElementsByTagName("body")[0].scrollTop;
    if(scrollPos &gt;= mydivpos)
        document.getElementById("noShow").className = "";
    else
        document.getElementById("noShow").className = "hidden";
};
&lt;/script&gt;
</code></pre>
