var img = new Array();

img[901] = new Image();  img[901].src="/images/menu_life.gif";
img[902] = new Image();  img[902].src="/images/menu_life_.gif";
img[903] = new Image();  img[903].src="/images/menu_yao.gif";
img[904] = new Image();  img[904].src="/images/menu_yao_.gif";
img[905] = new Image();  img[905].src="/images/menu_shisetsu.gif";
img[906] = new Image();  img[906].src="/images/menu_shisetsu_.gif";
img[907] = new Image();  img[907].src="/images/menu_shisei.gif";
img[908] = new Image();  img[908].src="/images/menu_shisei_.gif";
img[909] = new Image();  img[909].src="/images/menu_jigyosha.gif";
img[910] = new Image();  img[910].src="/images/menu_jigyosha_.gif";
img[911] = new Image();  img[911].src="/images/menu_top.gif";
img[912] = new Image();  img[912].src="/images/menu_top_.gif";

function change_image(nam,num) {
        if(navigator.appVersion.charAt(0)>= 3) {
                document.images[nam].src = img[num].src;
        }
}