if (document.images) {
b1on = new Image();
b1on.src = "../img_common/b1p.gif";
b2on = new Image();
b2on.src = "../img_common/b2p.gif";
b3on = new Image();
b3on.src = "../img_common/b3p.gif";
b4on = new Image();
b4on.src = "../img_common/b4p.gif";
b5on = new Image();
b5on.src = "../img_common/b5p.gif";
b6on = new Image();
b6on.src = "../img_common/b6p.gif";
b7on = new Image();
b7on.src = "../img_common/b7p.gif";
b8on = new Image();
b8on.src = "../img_common/b8p.gif";

b1off = new Image();
b1off.src = "../img_common/b1.gif";
b2off = new Image();
b2off.src = "../img_common/b2.gif";
b3off = new Image();
b3off.src = "../img_common/b3.gif";
b4off = new Image();
b4off.src = "../img_common/b4.gif";
b5off = new Image();
b5off.src = "../img_common/b5.gif";
b6off = new Image();
b6off.src = "../img_common/b6.gif";
b7off = new Image();
b7off.src = "../img_common/b7.gif";
b8off = new Image();
b8off.src = "../img_common/b8.gif";

}

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

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

}