var tabdropdown =
{
    disappeardelay: 200,        // hide menu delay on mouse out
    disablemenuclick: false,    //disable menu item's link when user clicks on a menu item with a drop down menu.
    enableiframeshim: 1,        // 1 = true, 0 = false

    dropmenuobj: null, ie: document.all, firefox: document.getElementById&&!document.all, previousmenuitem:null,
    currentpageurl: window.location.href.replace("http://"+window.location.hostname, "").replace(/^\//, ""), //get current page url (minus hostname: http://www.hostname.com/)

    getposOffset:function(what, offsettype)
    {
        var totaloffset = (offsettype == "left") ? what.offsetLeft : what.offsetTop;
        var parentEl = what.offsetParent;
        while (parentEl != null) {
            totaloffset = (offsettype == "left") ? totaloffset + parentEl.offsetLeft : totaloffset + parentEl.offsetTop;
            parentEl = parentEl.offsetParent;
        }
        return totaloffset;
    },

    //obj refers to drop down menu, obj2 refers to tab menu item mouse is currently over
    showhide:function(obj, e, obj2)
    {
        if (this.ie || this.firefox)
        this.dropmenuobj.style.left = this.dropmenuobj.style.top = "-500px"
        if (e.type == "click" && obj.visibility == hidden || e.type == "mouseover")
        {
            if (obj2.parentNode.className.indexOf("default") == -1) //if tab isn't a default selected one
                obj2.parentNode.className = "selected"
            obj.visibility = "visible"
        }
        else if (e.type == "click")
            obj.visibility = "hidden"
    },

    iecompattest:function()
    {
        return (document.compatMode && document.compatMode != "BackCompat") ? document.documentElement : document.body
    },

    clearbrowseredge:function(obj, whichedge)
    {
        var edgeoffset = 0
        if (whichedge == "rightedge")
        {
            var windowedge = this.ie && !window.opera ? this.standardbody.scrollLeft + this.standardbody.clientWidth - 15 : window.pageXOffset + window.innerWidth - 15
            this.dropmenuobj.contentmeasure = this.dropmenuobj.offsetWidth
            if (windowedge - this.dropmenuobj.x < this.dropmenuobj.contentmeasure)  //move menu to the left?
                edgeoffset = this.dropmenuobj.contentmeasure-obj.offsetWidth
        }
        else
        {
            var topedge = this.ie && !window.opera? this.standardbody.scrollTop : window.pageYOffset
            var windowedge = this.ie && !window.opera? this.standardbody.scrollTop+this.standardbody.clientHeight - 15 : window.pageYOffset+window.innerHeight - 18
            this.dropmenuobj.contentmeasure = this.dropmenuobj.offsetHeight
            if (windowedge-this.dropmenuobj.y < this.dropmenuobj.contentmeasure)
            { //move up?
                edgeoffset = this.dropmenuobj.contentmeasure+obj.offsetHeight
                if ((this.dropmenuobj.y - topedge) < this.dropmenuobj.contentmeasure) //up no good either?
                    edgeoffset = this.dropmenuobj.y + obj.offsetHeight - topedge
            }
            this.dropmenuobj.firstlink.style.borderTopWidth = (edgeoffset == 0)? 0 : "1px" //Add 1px top border to menu if dropping up
        }
        return edgeoffset
    },

    dropit:function(obj, e, dropmenuID)
    {
        if (this.dropmenuobj!=null)
        { //hide previous menu
            this.dropmenuobj.style.visibility="hidden" //hide menu
            if (this.previousmenuitem != null && this.previousmenuitem != obj)
            {
                if (this.previousmenuitem.parentNode.className.indexOf("default") == -1) //If the tab isn't a default selected one
                   this.previousmenuitem.parentNode.className = ""
            }
        }
        this.clearhidemenu()
        if (this.ie || this.firefox)
        {
            obj.onmouseout = function() { tabdropdown.delayhidemenu(obj) }
            obj.onclick = function() { return !tabdropdown.disablemenuclick } //disable main menu item link onclick?
            this.dropmenuobj = document.getElementById(dropmenuID)
            this.dropmenuobj.onmouseover = function() {tabdropdown.clearhidemenu() }
            this.dropmenuobj.onmouseout = function(e) { tabdropdown.dynamichide(e, obj) }
            this.dropmenuobj.onclick = function() { tabdropdown.delayhidemenu(obj) }
            this.showhide(this.dropmenuobj.style, e, obj)
            this.dropmenuobj.x = this.getposOffset(obj, "left")
            this.dropmenuobj.y = this.getposOffset(obj, "top")
            this.dropmenuobj.style.left = this.dropmenuobj.x - this.clearbrowseredge(obj, "rightedge") + "px"
            this.dropmenuobj.style.top = this.dropmenuobj.y - this.clearbrowseredge(obj, "bottomedge") + obj.offsetHeight + 1 + "px"
            this.previousmenuitem = obj //remember main menu item mouse moved out from (and into current menu item)
            this.positionshim() //call iframe shim function
        }
    },

    contains_firefox:function(a, b)
    {
        while (b.parentNode)
        if ((b = b.parentNode) == a)
            return true;
        return false;
    },

    dynamichide:function(e, obj2)
    { //obj2 refers to tab menu item mouse is currently over
        var evtobj = window.event ? window.event : e
        if (this.ie && !this.dropmenuobj.contains(evtobj.toElement))
            this.delayhidemenu(obj2)
        else if (this.firefox && e.currentTarget != evtobj.relatedTarget && !this.contains_firefox(evtobj.currentTarget, evtobj.relatedTarget))
            this.delayhidemenu(obj2)
    },

    delayhidemenu:function(obj2)
    {
        this.delayhide = setTimeout(
            function()
            {
                tabdropdown.dropmenuobj.style.visibility = 'hidden';
                if (obj2.parentNode.className.indexOf('default') == -1)
                    obj2.parentNode.className = ''
            },
            this.disappeardelay) //hide menu
    },

    clearhidemenu:function()
    {
        if (this.delayhide != "undefined")
            clearTimeout(this.delayhide)
    },

    positionshim:function()
    { //display iframe shim function
        if (this.enableiframeshim && typeof this.shimobject != "undefined")
        {
            if (this.dropmenuobj.style.visibility=="visible")
            {
                this.shimobject.style.width = this.dropmenuobj.offsetWidth + "px"
                this.shimobject.style.height = this.dropmenuobj.offsetHeight + "px"
                this.shimobject.style.left = this.dropmenuobj.style.left
                this.shimobject.style.top = this.dropmenuobj.style.top
            }
            this.shimobject.style.display = (this.dropmenuobj.style.visibility == "visible") ? "block" : "none"
        }
    },

    hideshim:function()
    {
        if (this.enableiframeshim && typeof this.shimobject != "undefined")
            this.shimobject.style.display = 'none'
    },

    isSelected:function(menuurl)
    {
        var menuurl = menuurl.replace("http://"+menuurl.hostname, "").replace(/^\//, "")
        return (tabdropdown.currentpageurl == menuurl)
    },

    init:function(menuid, dselected)
    {
        this.standardbody = (document.compatMode == "CSS1Compat") ? document.documentElement : document.body //create reference to common "body" across doctypes
        var menuitems = document.getElementById(menuid).getElementsByTagName("a")
        for (var i = 0; i < menuitems.length; i++)
        {
            if (menuitems[i].getAttribute("rel"))
            {
                var relvalue=menuitems[i].getAttribute("rel")
                document.getElementById(relvalue).firstlink = document.getElementById(relvalue).getElementsByTagName("a")[0]
                menuitems[i].onmouseover = function(e)
                {
                    var event = typeof e != "undefined" ? e : window.event
                    tabdropdown.dropit(this, event, this.getAttribute("rel"))
                }
            }
            if (dselected == "auto" && typeof setalready == "undefined" && this.isSelected(menuitems[i].href))
            {
                menuitems[i].parentNode.className += " selected default"
                var setalready = true
            }
            else if (parseInt(dselected) == i)
                menuitems[i].parentNode.className += " selected default"
        }
    }
}