var tmr = 2000;
var to = window.setTimeout("moveSlides()", tmr);
var nSlides = 3;
var curSlide = 1;
var dir = 1;
var spd = 1.6;
var lft = 0;
var doExit = false;

function moveSlides() {

    if (lft == 0 || lft > 644) {
        if (curSlide > 0 && curSlide <= nSlides)
            var elem = getElement("slide" + curSlide);

        if (!(doExit && dir == -1)) curSlide += dir;

        if ((curSlide > nSlides && dir == 1) || (curSlide == 1 && dir == -1)) {
            dir = -dir;
            curSlide = dir == 1 ? 1 : nSlides;
            if (curSlide == 1 && !doExit) {
                // end of slide show...
                toggleButtons();
                doExit = true;
                return;
            }
        }
        lft = dir == 1 ? 644 : 3;
    }

    elem = getElement("slide" + curSlide);

    lft = parseInt(dir == 1 ? (lft / spd) : (lft * spd));
    elem.style.left = lft + "px";

    if (lft < 644 && dir == -1)
        to = window.setTimeout("moveSlides()", 20);

    else if (lft > 0 && dir == 1)
        to = window.setTimeout("moveSlides()", 20);

    else {
        if (!doExit)
            to = window.setTimeout("moveSlides()", tmr);
        else {
            toggleButtons();
            return;
        }
    }
}

function moveSlide(newDir) {
    var allow = false;
    var elem;
    dir = newDir;

    if (dir == 1)
        elem = getElement("nxtslide")

    else
        elem = getElement("preslide");

    allow = elem.className == "";

    if (allow) {
        elem.className = "disabled";
        moveSlides();
    }
}

function toggleButtons() {
    if (dir == -1) curSlide--;
    // allow move to previous
    var elem = getElement("preslide");
    elem.className = curSlide > 1 ? "" : "disabled";
    // allow move to next
    elem = getElement("nxtslide");
    elem.className = curSlide < nSlides ? "" : "disabled";
}