var miniTab = {
    currentTab: 0,
    activeTab: 0,
    destX: 0,
    destW: 0,
    t: 0,
    b: 0,
    c: 0,
    d: 20,
    animInterval: null,
    sliderObj: null,
    aHeight: 0,

    init: function () {
        if (!document.getElementById || !document.getElementById("miniflex")) return;

        var ul = document.getElementById("miniflex");
        var liArr = ul.getElementsByTagName("li");
        var aArr = ul.getElementsByTagName("a");

        for (var i = 0, li; li = liArr[i]; i++) {
            liArr[i].onmouseover = aArr[i].onfocus = function (e) {
                var pos = 0;
                var elem = this.nodeName == "LI" ? this : this.parentNode;
                while (elem.previousSibling) {
                    elem = elem.previousSibling;
                    if (elem.tagName && elem.tagName == "LI") pos++;
                }
                miniTab.initSlide(pos);
            }
        }

        ul.onmouseout = function (e) {
            miniTab.initSlide(miniTab.currentTab);
        };

        for (var i = 0; i < aArr.length; i++) {
            if (document.location.href.indexOf(aArr[i].href) >= 0) {
                miniTab.activeTab = miniTab.currentTab = i;
            }
            aArr[i].style.borderBottom = "0px";
            aArr[i].style.paddingBottom = "6px";
        }

        miniTab.slideObj = ul.parentNode.appendChild(document.createElement("div"));
        miniTab.slideObj.appendChild(document.createTextNode(String.fromCharCode(160)));
        miniTab.slideObj.id = "animated-tab";
        miniTab.slideObj.style.top = (ul.offsetTop + liArr[miniTab.activeTab].offsetTop + aArr[miniTab.activeTab].offsetTop) + "px";
        miniTab.slideObj.style.left = (ul.offsetLeft + +liArr[miniTab.activeTab].offsetLeft + aArr[miniTab.activeTab].offsetLeft) + "px";
        miniTab.slideObj.style.width = aArr[miniTab.activeTab].offsetWidth + "px";
        miniTab.aHeight = ul.offsetTop + liArr[miniTab.activeTab].offsetTop + aArr[miniTab.activeTab].offsetTop;

        miniTab.initSlide(miniTab.activeTab, true);

        var intervalMethod = function () { miniTab.slideIt(); }
        miniTab.animInterval = setInterval(intervalMethod, 10);
    },

    cleanUp: function () {
        clearInterval(miniTab.animInterval);
        miniTab.animInterval = null;
    },

    initSlide: function (pos, force) {
        if (!force && pos == miniTab.activeTab) return;
        miniTab.activeTab = pos;
        miniTab.initAnim();
    },

    initAnim: function () {
        var ul = document.getElementById("miniflex");
        var liArr = ul.getElementsByTagName("li");
        var aArr = ul.getElementsByTagName("a");
        miniTab.destX = parseInt(liArr[miniTab.activeTab].offsetLeft + liArr[miniTab.activeTab].getElementsByTagName("a")[0].offsetLeft + ul.offsetLeft);
        miniTab.destW = parseInt(liArr[miniTab.activeTab].getElementsByTagName("a")[0].offsetWidth);
        miniTab.t = 0;
        miniTab.b = miniTab.slideObj.offsetLeft;
        miniTab.c = miniTab.destX - miniTab.b;
        miniTab.bW = miniTab.slideObj.offsetWidth;
        miniTab.cW = miniTab.destW - miniTab.bW;
        miniTab.slideObj.style.top = (ul.offsetTop + liArr[miniTab.activeTab].offsetTop + aArr[miniTab.activeTab].offsetTop) + "px";
    },

    slideIt: function () {
        var ul = document.getElementById("miniflex");
        var liArr = ul.getElementsByTagName("li");
        var aArr = ul.getElementsByTagName("a");

        // Has the browser text size changed?
        if (miniTab.aHeight != ul.offsetTop + liArr[miniTab.activeTab].offsetTop + aArr[miniTab.activeTab].offsetTop) {
            miniTab.initAnim();
            miniTab.aHeight = ul.offsetTop + liArr[miniTab.activeTab].offsetTop + aArr[miniTab.activeTab].offsetTop
        };

        if (miniTab.t++ < miniTab.d) {
            var x = miniTab.animate(miniTab.t, miniTab.b, miniTab.c, miniTab.d);
            var w = miniTab.animate(miniTab.t, miniTab.bW, miniTab.cW, miniTab.d);
            miniTab.slideObj.style.left = parseInt(x) + "px";
            miniTab.slideObj.style.width = parseInt(w) + "px";
        } else {
            miniTab.slideObj.style.left = miniTab.destX + "px";
            miniTab.slideObj.style.width = miniTab.destW + "px";
        }
    },

    animate: function (t, b, c, d) {
        if ((t /= d / 2) < 1) return c / 2 * t * t + b;
        return -c / 2 * ((--t) * (t - 2) - 1) + b;
    }
}

window.onload = miniTab.init;
window.onunload = miniTab.cleanUp;