function flipimage(image)
{
    document.getElementById('foto01').style.visibility = "hidden";
    document.getElementById('foto02').style.visibility = "hidden";
    document.getElementById('foto03').style.visibility = "hidden";
    document.getElementById('foto04').style.visibility = "hidden";

    document.getElementById(image).style.visibility = "visible";
}

function hideimage(image)
{
    document.getElementById(image).style.visibility = "hidden";
}