var exListTimer = window.setInterval(loadExList, 500)

function isFile(str) {
    var O = AJ();
    if (!O) return false;
    try {
        O.open("HEAD", str, false);
        O.send(null);
        return (O.status == 200) ? true : false;
    }
    catch (er) {
        return false;
    }
}
function AJ() {
    var obj;
    if (window.XMLHttpRequest) {
        obj = new XMLHttpRequest();
    }
    else if (window.ActiveXObject) {
        try {
            obj = new ActiveXObject('MSXML2.XMLHTTP.3.0');
        }
        catch (er) {
            obj = false;
        }
    }
    return obj;
}

function exHeader(html) {
    var x = html.indexOf('<');
    if (x > 0) {
        return html.substring(0, x);
    } else {
        return null;
    }
}
function exDescription(html) {
    var x = html.indexOf('<');
    if (x > 0) {
        return html.substring(x+8);
    } else {
        return null;
    }
}

function getexDesc(header) {
    var ps = document.getElementsByTagName('p');
    for (i = 0; i < ps.length; i++) {
        if (ps[i].className == 'exDesc') {
          if (exHeader(ps[i].innerHTML)==header)
            return('<h4>'+header+'</h4>'+exDescription(ps[i].innerHTML));
        }
    }
    return null
}

function loadExList() {
    window.clearInterval(exListTimer);
    var opt = document.getElementById('exhDropDown');
    var ps = document.getElementsByTagName('p');
    for (i = 0; i < ps.length; i++) {
        if (ps[i].className == 'exDesc') {
          var header = exHeader(ps[i].innerHTML);
          if (header) {
              opt.options[opt.options.length] = new Option(header, header, false, true);
          }
      }
    }
    opt.selectedIndex = 0;
}

function swapexImg(header) {
    String.prototype.trim = function() { return this.replace(/^\s*/, "").replace(/\s*$/, ""); }
    header=header.replace('\n','');
    header=header.trim();
    var src = 'images/excersizes/' + header + '.jpg';
    var Pic = new Image();
    Pic.src = src;
    if (isFile(src) || (!document.all)) {
        if (document.all) {
            document.images.exImg.style.filter = "blendTrans(duration=2)";
            document.images.exImg.style.filter = "blendTrans(duration=crossFadeDuration)";
            document.images.exImg.filters.blendTrans.Apply();
        }
        document.images.exImg.src = src;
        if (document.all) {
            document.images.exImg.filters.blendTrans.Play()
        } 
    }
}

function updateEX() {
    var opt = document.getElementById('exhDropDown');
    var header = (opt.options[opt.selectedIndex].value);
    var desc = getexDesc(header);
    if (desc) {
        objDesc = document.getElementById('exDesc');
        objDesc.innerHTML = desc;
        swapexImg(header);
    }
}

function padzero(i) {
    var s;
    s = i.toString();
    if (s.length == 1) s = '0' + s;
    return s;
}

function donothing() {
    var slideShowSpeed = 4000
    var crossFadeDuration = 3
    var Pic = new Array()

    var x = 0;
    for (i = 0; i < 20; i++) {
        var s = 'images/homeimages/p' + padzero(i + 1) + '.jpg';
        if (isFile(s)) {
            Pic[x] = s;
            x++;
        }
    }

    var t
    var j = 0
    var p = Pic.length

    var preLoad = new Array()
    for (i = 0; i < p; i++) {
        preLoad[i] = new Image()
        preLoad[i].src = Pic[i]

    }
}

function runSlideShow() {
    window.clearInterval(timer);
    if (document.all) {
        document.images.SlideShow.style.filter = "blendTrans(duration=2)";
        document.images.SlideShow.style.filter = "blendTrans(duration=crossFadeDuration)";
        document.images.SlideShow.filters.blendTrans.Apply();
    }
    document.images.SlideShow.src = preLoad[j].src
    if (document.all) {
        document.images.SlideShow.filters.blendTrans.Play()
    }
    j = j + 1
    if (j > (p - 1)) j = 0
    t = setTimeout('runSlideShow()', slideShowSpeed)
}