topon = new Image(120,150);
topoff = new Image(120,150);
topon.src = 'images/top_on.jpg';
topoff.src = 'images/top_off.jpg';

abouton = new Image(120,150);
aboutoff = new Image(120,150);
abouton.src = 'images/about_on.jpg';
aboutoff.src = 'images/about_off.jpg';

scheduleon = new Image(120,150);
scheduleoff = new Image(120,150);
scheduleon.src = 'images/schedule_on.jpg';
scheduleoff.src = 'images/schedule_off.jpg';

mapon = new Image(120,150);
mapoff = new Image(120,150);
mapon.src = 'images/map_on.jpg';
mapoff.src = 'images/map_off.jpg';

mailon = new Image(120,150);
mailoff = new Image(120,150);
mailon.src = 'images/mail_on.jpg';
mailoff.src = 'images/mail_off.jpg';

function swapImg(name,id){
	document[name].src = eval(id + ".src");
}