// preload images
// image folder
var imgf = 'http://hpplc.indiana.edu/images/nav/';

nav = new Array('1','2','3','4','5','6','7','8');
navover = new Array('o1','o2','o3','o4','o5','o6','o7','o8');

// main images
var counter = 1;
for (var counter = 1; counter < 8; counter++) {
	nav[counter] = new Image();
	nav[counter].src = imgf + 'nav_a_0' + counter + '.gif';
}

// mouse over images
var counter = 1;
for (var counter = 1; counter < 8; counter++) {
	navover[counter] = new Image();
	navover[counter].src = imgf + 'nav_b_0' + counter + '.gif';
}

function rollout(imgname, imgno){
document.images[imgname].src = nav[imgno].src;
return true;
}

function rollover(imgname, imgno){
document.images[imgname].src = navover[imgno].src;
return true;
}