img1on = new Image( );
img1on.src = "/image/3_mn01_on.gif";

img1off = new Image( );
img1off.src = "/image/3_mn01.gif";

img2on = new Image( );
img2on.src = "/image/3_mn02_on.gif";

img2off = new Image( );
img2off.src = "/image/3_mn02.gif";

img3on = new Image( );
img3on.src = "/image/3_mn03_on.gif";

img3off = new Image( );
img3off.src = "/image/3_mn03.gif";

function img_act(imgName) {
document [imgName].src = eval(imgName + "on.src");
}

function img_inact(imgName) {
document [imgName].src = eval(imgName + "off.src");
}