if (document.images) { 

var img6on = new Image();
img6on.src = "images/top/wanko_185baner2.jpg"; // ポイント時の画像
var img6off = new Image();
img6off.src = "images/top/wanko_185baner1.jpg"; // 通常の画像

var img7on = new Image();
img7on.src = "images/top/hokkaido_185baner2.jpg";
var img7off = new Image();
img7off.src = "images/top/hokkaido_185baner1.jpg";

var img8on = new Image();
img8on.src = "images/top/sora_185baner2.jpg";
var img8off = new Image();
img8off.src = "images/top/sora_185baner1.jpg";

} 

function On(name) { 
if (document.images) { 
document.images[name].src = eval(name + 'on.src'); 
} 
} 

function Off(name) { 
if (document.images) { 
document.images[name].src = eval(name + 'off.src'); 
} 
}