function rotateImage() 
{
    var elem = document.getElementById("bulletin");
    try {
        if (elem.className.length == 0 || elem.className == "bulletin")
            elem.className = "bulletin2";
        else
            elem.className = "bulletin";
    }
    catch (exc) { }
}

function startRotator() 
{
    rotateImage();
    setInterval('rotateImage()', 500);
}