function slideshow_rotate(strDirection) {
    var navLinks = document.getElementById("slideshow_links").getElementsByTagName("a");
    var index;
    for (i = 0; i < navLinks.length; i++) {
        var lnk = navLinks[i];
        if (strDirection == "next") 
        {
            if (navLinks[i + 1]) {
                index = i + 1;
            }
            else {
                index = 0;
            }
        }
        else
        {
            if (i == 0 || !navLinks[i - 1]) {
                index = navLinks.length - 1;
            }
            else {
                index = i - 1;
            }
        }

        if (lnk.getAttribute("class") == "selected" || lnk.getAttribute("className") == "selected") {
            slideshow_changeDisplay(navLinks[index].id);
        }
    }
}

function slideshow_changeDisplay(strLinkID) {
    var lnkPrev = document.getElementById("lnkPrev");
    var lnkNext = document.getElementById("lnkNext");
    var navLinks = document.getElementById("slideshow_links").getElementsByTagName("a");
    for (i = 0; i < navLinks.length; i++) {
        var lnk = navLinks[i];
        var img = document.getElementById("img" + lnk.id.substring(3));
        if (lnk.id == strLinkID) {
            img.style.display = "inline";
            lnk.setAttribute("class", "selected");
            lnk.setAttribute("className", "selected"); //hack for IE7
            lnkPrev.style.visibility = (i == 0) ? "hidden" : "";
            lnkNext.style.visibility = (i >= navLinks.length - 1) ? "hidden" : "";
        }
        else {
            img.style.display = "none";
            lnk.setAttribute("class", "");
            lnk.setAttribute("className", ""); //hack for IE7
        }
    }
}

function slideshow_next() {
    slideshow_rotate("next");
    clearInterval(intVal);
}

function slideshow_prev() {
    slideshow_rotate("prev");
    clearInterval(intVal);
}

function slideshow_show(strLinkID) {
    slideshow_changeDisplay(strLinkID);
    clearInterval(intVal);
}