if(document.images) {
pics = new Array(); 
pics[1] = new Image();
pics[1].src = "wp-content/themes/fantasystory/images/bt_notes1.gif"; 
pics[2] = new Image();
pics[2].src = "wp-content/themes/fantasystory/images/bt_notes2.gif";
pics[3] = new Image();
pics[3].src = "wp-content/themes/fantasystory/images/bt_comments1.gif";
pics[4] = new Image();
pics[4].src = "wp-content/themes/fantasystory/images/bt_comments2.gif";
}

function changer(from,to) {
if(document.images) {
document.images[from].src = pics[to].src;
}
}