function shiftImages(buf)
{
    var overflow = buf[0];
    for (var i = 0; i < buf.length - 1; i++)
        buf[i] = buf[i + 1];
    buf[buf.length - 1] = overflow;
}

function setImageClasses(buf, class0, classN)
{
    document.getElementById(buf[0]).className = class0;
    for (var i = 1; i < buf.length; i++)
        document.getElementById(buf[i]).className = classN;
}

function changeImage(buf)
{
    var class0 = document.getElementById(buf[0]).className;
    var classN = document.getElementById(buf[1]).className;
    shiftImages(buf);
    setImageClasses(buf, class0, classN);
}

function cycleThroughImages(buf, buf_name, class0, classN, delay)
{
    setImageClasses(buf, class0, classN);
    setInterval("changeImage(" + buf_name + ")", delay);
}