fnMenu = Array(
 "images/menu_hello.jpg",
 "images/menu_hello_a.jpg",
 "images/menu_secure.jpg",
 "images/menu_secure_a.jpg",
 "images/menu_shien.jpg",
 "images/menu_shien_a.jpg",
 "images/menu_kyosan.jpg",
 "images/menu_kyosan_a.jpg",
 "images/menu_link.jpg",
 "images/menu_link_a.jpg",
 "images/menu_contact.jpg",
 "images/menu_contact_a.jpg"
);

filenames = {
 'mn' : fnMenu
};

images = new Object();

function Over(prefix, id)
{
 targetImg = document.getElementById(prefix + id);
 targetImg.src = images[prefix][id + id - 1].src;
}

function Out(prefix, id)
{
 targetImg = document.getElementById(prefix + id);
 targetImg.src = images[prefix][id + id - 2].src;
}

function initialize()
{
    for (i in filenames) {
      images[i] = new Array();
      for (j = 0; j < filenames[i].length; j++) {
        images[i][j] = new Image();
        images[i][j].src = filenames[i][j];
      }
    }
}