function mousein(i) {
    if (i < 10) {
        var pic = document.getElementById("top" + i);
        pic.style.visibility = "visible";
    }
    else {
        i = i - 10;
        var pic = document.getElementById("bot" + i);
        pic.style.visibility = "visible";
    }
}

function mouseout(i) {
    if (i < 10) {
        var pic = document.getElementById("top" + i);
        pic.style.visibility = "hidden";
    }
    else {
        i = i - 10;
        var pic = document.getElementById("bot" + i);
        pic.style.visibility = "hidden";
    }
}