about_off = new Image();
about_off.src = "/images/topnav/about_off.gif";

about_over = new Image();
about_over.src = "/images/topnav/about_over.gif";

about_in = new Image();
about_in.src = "/images/topnav/about_in.gif";

academics_off = new Image();
academics_off.src = "/images/topnav/academics_off.gif";

academics_over = new Image();
academics_over.src = "/images/topnav/academics_over.gif";

academics_in = new Image();
academics_in.src = "/images/topnav/academics_in.gif";

athletics_off = new Image();
athletics_off.src = "/images/topnav/athletics_off.gif";

athletics_over = new Image();
athletics_over.src = "/images/topnav/athletics_over.gif";

athletics_in = new Image();
athletics_in.src = "/images/topnav/athletics_in.gif";

campuslife_off = new Image();
campuslife_off.src = "/images/topnav/campuslife_off.gif";

campuslife_over = new Image();
campuslife_over.src = "/images/topnav/campuslife_over.gif";

campuslife_in = new Image();
campuslife_in.src = "/images/topnav/campuslife_in.gif";

admissions_off = new Image();
admissions_off.src = "/images/topnav/admissions_off.gif";

admissions_over = new Image();
admissions_over.src = "/images/topnav/admissions_over.gif";

admissions_in = new Image();
admissions_in.src = "/images/topnav/admissions_in.gif";

calendar_off = new Image();
calendar_off.src = "/images/topnav/calendar_off.gif";

calendar_over = new Image();
calendar_over.src = "/images/topnav/calendar_over.gif";

calendar_in = new Image();
calendar_in.src = "/images/topnav/calendar_in.gif";

news_off = new Image();
news_off.src = "/images/topnav/news_off.gif";

news_over = new Image();
news_over.src = "/images/topnav/news_over.gif";

news_in = new Image();
news_in.src = "/images/topnav/news_in.gif";

contact_off = new Image();
contact_off.src = "/images/topnav/contact_off.gif";

contact_over = new Image();
contact_over.src = "/images/topnav/contact_over.gif";

contact_in = new Image();
contact_in.src = "/images/topnav/contact_in.gif";

<!-- repeat the 4 lines above for any subsequent images. -->

function swap(){
if (document.images){
for (var x=0;
x<swap.arguments.length;
x+=2) {
document[swap.arguments[x]].src = eval(swap.arguments[x+1] + ".src");
}
}
}