var buttons = Array(8);
var buttons_a = Array(8);

function loadImage() {
	for (var i=0; i < 8 ; i++) {
		buttons[i] = new Image();
		buttons_a[i] = new Image();
	}

	buttons[1].src = "img/index_topics.jpg";
	buttons_a[1].src = "img/index_topics_a.jpg";
	buttons[2].src = "img/index_keep.jpg";
	buttons_a[2].src = "img/index_keep_a.jpg";
	buttons[3].src = "img/index_train.jpg";
	buttons_a[3].src = "img/index_train_a.jpg";
	buttons[4].src = "img/index_menu.jpg";
	buttons_a[4].src = "img/index_menu_a.jpg";
	buttons[5].src = "img/index_profile.jpg";
	buttons_a[5].src = "img/index_profile_a.jpg";
	buttons[6].src = "img/index_photo.jpg";
	buttons_a[6].src = "img/index_photo_a.jpg";
	buttons[7].src = "img/index_link.jpg";
	buttons_a[7].src = "img/index_link_a.jpg";
}

function swapImage(imgName,i) {
	var img = document.images[imgName];
	if (!img) img = findImage(document, imgName);
	if (buttons_a[i]) {
		img.src = buttons_a[i].src;
	} else {
		img.src = "img/index_" + imgName +  "_a.jpg";
	}
}

function returnImage(imgName,i) {
	var img = document.images[imgName];
	if (!img) img = findImage(document, imgName);
	if (buttons[i]) {
		img.src = buttons[i].src;
	} else {
		img.src = "img/index_" + imgName +  ".jpg";
	}
}

function findImage(doc, imgName)
{
  for (var i=0; i < doc.layers.length; i++)
  {
    var img = doc.layers[i].document.images[imgName];
    if (!img) img = findImage(doc.layers[i], imgName);
    if (img) return img;
  }
  return null;
}