var SLIDETIMER = 3;
var SLIDESPEED = 3;
var SCROLLTIMER = 3;
var SCROLLSPEED = 3;
var STARTINGOPACITY = 40;

// handles section to section scrolling of the content //
function slideContent(id, prefix, timer) {
    var div = document.getElementById(id);
    var slider = div.parentNode;
    clearInterval(slider.timer);
    slider.section = parseInt(id.replace(/\D/g, ''));
    slider.target = div.offsetTop;
    slider.style.top = slider.style.top || '0px';
    slider.current = slider.style.top.replace('px', '');
    slider.direction = (Math.abs(slider.current) > slider.target) ? 1 : -1;
    slider.style.opacity = STARTINGOPACITY * .01;
    slider.style.filter = 'alpha(opacity=' + STARTINGOPACITY + ')';
    slider.timer = setInterval(function() { slideAnimate(slider, prefix, timer) }, SLIDETIMER);
}

function slideContent2(id, prefix, timer) {
    var div = document.getElementById(id);
    var slider = div.parentNode;
    clearInterval(slider.timer);
    slider.section = parseInt(id.replace(/\D/g, ''));
    slider.target = div.offsetTop;
    slider.style.top = slider.style.top || '0px';
    slider.current = slider.style.top.replace('px', '');
    slider.direction = (Math.abs(slider.current) > slider.target) ? 1 : -1;
    slider.style.opacity = STARTINGOPACITY * .01;
    slider.style.filter = 'alpha(opacity=' + STARTINGOPACITY + ')';
    slider.timer = setInterval(function() { slideAnimate(slider, prefix, timer) }, SLIDETIMER);
}

function slideAnimate(slider, prefix, timer) {
    var curr = Math.abs(slider.current);
    var tar = Math.abs(slider.target);
    var dir = slider.direction;
    if ((tar - curr <= SLIDESPEED && dir == -1) || (curr - tar <= SLIDESPEED && dir == 1)) {
        slider.style.top = (slider.target * -1) + 'px';
        slider.style.opacity = 1;
        slider.style.filter = 'alpha(opacity=100)';
        clearInterval(slider.timer);
        if (slider.autoscroll) {
            setTimeout(function() { autoScroll(slider.id, prefix, timer) }, timer * 1000);
        }
    } else {
        var pos = (dir == 1) ? parseInt(slider.current) + SLIDESPEED : slider.current - SLIDESPEED;
        slider.current = pos;
        slider.style.top = pos + 'px';
    }
}

// handles manual scrolling of the content //
function scrollContent(id, dir) {
    var div = document.getElementById(id);
    clearInterval(div.timer);
    var sections = div.getElementsByTagName('div');
    var length = sections.length;
    var limit;
    if (dir == -1) {
        limit = 0;
    } else {
        if (length > 1) {
            limit = sections[length - 1].offsetTop;
        } else {
            limit = sections[length - 1].offsetHeight - div.parentNode.offsetHeight + 20;
        }
    }
    div.style.opacity = STARTINGOPACITY * .01;
    div.style.filter = 'alpha(opacity=' + STARTINGOPACITY + ')';
    div.timer = setInterval(function() { scrollAnimate(div, dir, limit) }, SCROLLTIMER);
}

// handles manual scrolling of the content in reverse//
function scrollContentReverse(id, dir) {
    var div = document.getElementById(id);
    clearInterval(div.timer);
    var sections = div.getElementsByTagName('div');
    var length = sections.length;
    var limit;
    if (dir == +1) {
        limit = 0;
    } else {
        if (length > 1) {
            limit = sections[length - 1].offsetTop;
        } else {
            limit = sections[length - 1].offsetHeight - div.parentNode.offsetHeight + 20;
        }
    }
    div.style.opacity = STARTINGOPACITY * .01;
    div.style.filter = 'alpha(opacity=' + STARTINGOPACITY + ')';
    div.timer = setInterval(function() { scrollAnimate(div, dir, limit) }, SCROLLTIMER);
}

function scrollAnimate(div, dir, limit) {
    div.style.top = div.style.top || '0px';
    var top = div.style.top.replace('px', '');
    if (dir == 1) {
        if (limit - Math.abs(top) <= SCROLLSPEED) {
            cancelScroll(div.id);
            div.style.top = '-' + limit + 'px';
        } else {
            div.style.top = top - SCROLLSPEED + 'px';
        }
    } else {
        if (Math.abs(top) - limit <= SCROLLSPEED) {
            cancelScroll(div.id);
            div.style.top = limit + 'px';
        } else {
            div.style.top = parseInt(top) + SCROLLSPEED + 'px';
        }
    }
}

// cancel the scrolling on mouseout //
function cancelScroll(id) {
    var div = document.getElementById(id);
    div.style.opacity = 1;
    div.style.filter = 'alpha(opacity=100)';
    clearTimeout(div.timer);
}

// initiate auto scrolling //
function autoScroll(id, prefix, timer, restart) {
    var div = document.getElementById(id);
    div.autoscroll = (!div.autoscroll && !restart) ? false : true;
    if (div.autoscroll) {
        var sections = div.getElementsByTagName('div');
        var length = sections.length;
        div.section = (div.section && div.section < length) ? div.section + 1 : 1;
        slideContent(prefix + '-' + div.section, prefix, timer);
    }
}

// initiate auto scrolling //
function autoScrollRev(id, prefix, timer, restart) {
    var div = document.getElementById(id);
    div.autoscroll = false;
    div.autoscrollrev = (!div.autoscrollrev && !restart) ? false : true;
    if (div.autoscrollrev) {
        var sections = div.getElementsByTagName('div');
        var length = sections.length;
        div.section = (div.section && div.section > 1) ? div.section - 1 : length;
        slideContent2(prefix + '-' + div.section, prefix, timer);
    }
}

// cancel automatic scrolling //
function cancelAutoScroll(id) {
    var div = document.getElementById(id);
    div.autoscroll = false;
}