Javascript getElementById Error in Header

Hi,

I’m having trouble with a javascript error at my site, http://www.onthebaseline.com.

Whenever a page loads in IE or Firefox, it posts an error message saying “document.getElementById (“topnav”) has no properties. Line 110)” in Firefox and “document.getElementById(….) is null or not an object”, also on Line 110 in IE.

I suspect the problem has to do with our drop-down header javascript code, which I have copied below. Could someone please tell me what needs to be changed in hopes of getting rid of the error message. Thank you!!!!

<script type=”text/javascript” src=”http://www.onthebaseline.com/wp-content/themes/Simplicity10/ruthsarian_utilities.js”></script&gt;
<script type=”text/javascript”>
<!–
event_attach( ‘onload’ , function () {
sfHover( ‘nav-menu’ );
} );
//–>
</script>

<script type=”text/javascript” src=”<?php bloginfo(‘stylesheet_directory’); ?>/js/tabber.js”></script>
<script type=”text/javascript” src=”<?php bloginfo(‘stylesheet_directory’); ?>/js/prototype.js”></script>
<script type=”text/javascript” src=”<?php bloginfo(‘stylesheet_directory’); ?>/js/effects.js”></script>
<script type=”text/javascript” src=”<?php bloginfo(‘stylesheet_directory’); ?>/js/glider.js”></script>

<script type=”text/javascript”><!–//–><![CDATA[//><!–
sfHover = function() {
var sfEls = document.getElementById(“nav”).getElementsByTagName(“LI”);
for (var i=0; i<sfEls.length; i++) {
sfEls[i].onmouseover=function() {
this.className+=” sfhover”;
}
sfEls[i].onmouseout=function() {
this.className=this.className.replace(new RegExp(” sfhover\\b”), “”);
}
}
}
if (window.attachEvent) window.attachEvent(“onload”, sfHover);
//–><!]]></script>

<script type=”text/javascript”><!–//–><![CDATA[//><!–
sfHover = function() {
var sfEls = document.getElementById(“topnav”).getElementsByTagName(“LI”);
for (var i=0; i<sfEls.length; i++) {
sfEls[i].onmouseover=function() {
this.className+=” sfhover”;
}
sfEls[i].onmouseout=function() {
this.className=this.className.replace(new RegExp(” sfhover\\b”), “”);
}
}
}
if (window.attachEvent) window.attachEvent(“onload”, sfHover);
//–><!]]></script>

<script type=”text/javascript”>
function display(id) {
if (document.getElementById(id).style.display == ‘block’) {
document.getElementById(id).style.display = ‘none’;
} else {
document.getElementById(id).style.display = ‘block’;
}
return false;
}
</script>

<script type=”text/javascript”>
function display(id) {
if (document.getElementById(id).style.display == ‘block’) {
document.getElementById(id).style.display = ‘none’;
} else {
document.getElementById(id).style.display = ‘block’;
}
return false;
}
</script>