b1over = new Image();
b1over.src="images/navigation/btn_01b.gif";

b2over = new Image();
b2over.src="images/navigation/btn_02b.gif";

b3over = new Image();
b3over.src="images/navigation/btn_03b.gif";

b4over = new Image();
b4over.src="images/navigation/btn_04b.gif";

b5over = new Image();
b5over.src="images/navigation/btn_05b.gif";

function swap(a)
{
document.images[a].src=eval("b"+a+"over.src");
}

function bswap(a)
{
document.images[a].src="images/navigation/btn_0"+a+"a.gif";
}