//** Chrome Drop Down Menu- Author: Dynamic Drive (http://www.dynamicdrive.com)

//** Updated: July 14th 06' to v2.0
//1) Ability to "left", "center", or "right" align the menu items easily, just by modifying the CSS property "text-align".
//2) Added an optional "swipe down" transitional effect for revealing the drop down menus.
//3) Support for multiple Chrome menus on the same page.

//** Updated: Nov 14th 06' to v2.01- added iframe shim technique

//** Updated: July 23rd, 08 to v2.4
//1) Main menu items now remain "selected" (CSS class "selected" applied) when user moves mouse into corresponding drop down menu. 
//2) Adds ability to specify arbitrary HTML that gets added to the end of each menu item that carries a drop down menu (ie: a down arrow image).
//3) All event handlers added to the menu are now unobstrusive, allowing you to define your own "onmouseover" or "onclick" events on the menu items.
//4) Fixed elusive JS error in FF that sometimes occurs when mouse quickly moves between main menu items and drop down menus

//** Updated: Oct 29th, 08 to v2.5 (only .js file modified from v2.4)
//1) Added ability to customize reveal animation speed (# of steps)
//2) Menu now works in IE8 beta2 (a valid doctype at the top of the page is required)
// <img src="/images/down.gif" border="0" />
var cssdropdown = {
    disappeardelay: 250, //set delay in miliseconds before menu disappears onmouseout
    dropdownindicator: '', //specify full HTML to add to end of each menu item with a drop down menu
    enablereveal: [true, 8], //enable swipe effect? [true/false, steps (Number of animation steps. Integer between 1-20. Smaller=faster)]
    enableiframeshim: 1, //enable "iframe shim" in IE5.5 to IE7? (1=yes, 0=no)

    //No need to edit beyond here////////////////////////

    dropmenuobj: null, asscmenuitem: null, domsupport: document.all || document.getElementById, standardbody: null, iframeshimadded: false, revealtimers: {},

    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;
    },

    css: function(el, targetclass, action) {
        var needle = new RegExp("(^|\\s+)" + targetclass + "($|\\s+)", "ig")
        if (action == "check")
            return needle.test(el.className)
        else if (action == "remove")
            el.className = el.className.replace(needle, "")
        else if (action == "add" && !needle.test(el.className))
            el.className += " " + targetclass
    },

    showmenu: function(dropmenu, e) {
        if (this.enablereveal[0]) {
            if (!dropmenu._trueheight || dropmenu._trueheight < 10)
                dropmenu._trueheight = dropmenu.offsetHeight
            clearTimeout(this.revealtimers[dropmenu.id])
            dropmenu.style.height = dropmenu._curheight = 0
            dropmenu.style.overflow = "hidden"
            dropmenu.style.visibility = "visible"
            this.revealtimers[dropmenu.id] = setInterval(function() { cssdropdown.revealmenu(dropmenu) }, 10)
        }
        else {
            dropmenu.style.visibility = "visible"
        }
        this.css(this.asscmenuitem, "selected", "add")
    },

    revealmenu: function(dropmenu, dir) {
        var curH = dropmenu._curheight, maxH = dropmenu._trueheight, steps = this.enablereveal[1]
        if (curH < maxH) {
            var newH = Math.min(curH, maxH)
            dropmenu.style.height = newH + "px"
            dropmenu._curheight = newH + Math.round((maxH - newH) / steps) + 1
        }
        else { //if done revealing menu
            dropmenu.style.height = "auto"
            dropmenu.style.overflow = "hidden"
            clearInterval(this.revealtimers[dropmenu.id])
        }
    },

    clearbrowseredge: function(obj, whichedge) {
        var edgeoffset = 0
        if (whichedge == "rightedge") {
            var windowedge = document.all && !window.opera ? this.standardbody.scrollLeft + this.standardbody.clientWidth - 15 : window.pageXOffset + window.innerWidth - 15
            var dropmenuW = this.dropmenuobj.offsetWidth
            if (windowedge - this.dropmenuobj.x < dropmenuW)  //move menu to the left?
                edgeoffset = dropmenuW - obj.offsetWidth
        }
        else {
            var topedge = document.all && !window.opera ? this.standardbody.scrollTop : window.pageYOffset
            var windowedge = document.all && !window.opera ? this.standardbody.scrollTop + this.standardbody.clientHeight - 15 : window.pageYOffset + window.innerHeight - 18
            var dropmenuH = this.dropmenuobj._trueheight
            if (windowedge - this.dropmenuobj.y < dropmenuH) { //move up?
                edgeoffset = dropmenuH + obj.offsetHeight
                if ((this.dropmenuobj.y - topedge) < dropmenuH) //up no good either?
                    edgeoffset = this.dropmenuobj.y + obj.offsetHeight - topedge
            }
        }
        return edgeoffset
    },

    dropit: function(obj, e, dropmenuID) {
        if (this.dropmenuobj != null) //hide previous menu
            this.hidemenu() //hide menu
        this.clearhidemenu()
        this.dropmenuobj = document.getElementById(dropmenuID) //reference drop down menu
        this.asscmenuitem = obj //reference associated menu item
        this.showmenu(this.dropmenuobj, e)
        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.positionshim() //call iframe shim function
    },

    positionshim: function() { //display iframe shim function
        if (this.iframeshimadded) {
            if (this.dropmenuobj.style.visibility == "visible") {
                this.shimobject.style.width = this.dropmenuobj.offsetWidth + "px"
                this.shimobject.style.height = this.dropmenuobj._trueheight + "px"
                this.shimobject.style.left = parseInt(this.dropmenuobj.style.left) + "px"
                this.shimobject.style.top = parseInt(this.dropmenuobj.style.top) + "px"
                this.shimobject.style.display = "block"
            }
        }
    },

    hideshim: function() {
        if (this.iframeshimadded)
            this.shimobject.style.display = 'none'
    },

    isContained: function(m, e) {
        var e = window.event || e
        var c = e.relatedTarget || ((e.type == "mouseover") ? e.fromElement : e.toElement)
        while (c && c != m) try { c = c.parentNode } catch (e) { c = m }
        if (c == m)
            return true
        else
            return false
    },

    dynamichide: function(m, e) {
        if (!this.isContained(m, e)) {
            this.delayhidemenu()
        }
    },

    delayhidemenu: function() {
        this.delayhide = setTimeout("cssdropdown.hidemenu()", this.disappeardelay) //hide menu
    },

    hidemenu: function() {
        this.css(this.asscmenuitem, "selected", "remove")
        this.dropmenuobj.style.visibility = 'hidden'
        this.dropmenuobj.style.left = this.dropmenuobj.style.top = "-1000px"
        this.hideshim()
    },

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

    addEvent: function(target, functionref, tasktype) {
        if (target.addEventListener)
            target.addEventListener(tasktype, functionref, false);
        else if (target.attachEvent)
            target.attachEvent('on' + tasktype, function() { return functionref.call(target, window.event) });
    },

    startchrome: function() {
        if (!this.domsupport)
            return
        this.standardbody = (document.compatMode == "CSS1Compat") ? document.documentElement : document.body
        for (var ids = 0; ids < arguments.length; ids++) {
            var menuitems = document.getElementById(arguments[ids]).getElementsByTagName("a")
            for (var i = 0; i < menuitems.length; i++) {
                if (menuitems[i].getAttribute("rel")) {
                    var relvalue = menuitems[i].getAttribute("rel")
                    var asscdropdownmenu = document.getElementById(relvalue)
                    this.addEvent(asscdropdownmenu, function() { cssdropdown.clearhidemenu() }, "mouseover")
                    this.addEvent(asscdropdownmenu, function(e) { cssdropdown.dynamichide(this, e) }, "mouseout")
                    this.addEvent(asscdropdownmenu, function() { cssdropdown.delayhidemenu() }, "click")
                    try {
                        menuitems[i].innerHTML = menuitems[i].innerHTML + "" + this.dropdownindicator
                    } catch (e) { }
                    this.addEvent(menuitems[i], function(e) { //show drop down menu when main menu items are mouse over-ed
                        if (!cssdropdown.isContained(this, e)) {
                            var evtobj = window.event || e
                            cssdropdown.dropit(this, evtobj, this.getAttribute("rel"))
                        }
                    }, "mouseover")
                    this.addEvent(menuitems[i], function(e) { cssdropdown.dynamichide(this, e) }, "mouseout") //hide drop down menu when main menu items are mouse out
                    this.addEvent(menuitems[i], function() { cssdropdown.delayhidemenu() }, "click") //hide drop down menu when main menu items are clicked on
                }
            } //end inner for
        } //end outer for
        if (this.enableiframeshim && document.all && !window.XDomainRequest && !this.iframeshimadded) { //enable iframe shim in IE5.5 thru IE7?
            document.write('<IFRAME id="iframeshim" src="about:blank" frameBorder="0" scrolling="no" style="left:0; top:0; position:absolute; display:none;z-index:90; background: transparent;"></IFRAME>')
            this.shimobject = document.getElementById("iframeshim") //reference iframe object
            this.shimobject.style.filter = 'progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0)'
            this.iframeshimadded = true
        }
    } //end startchrome

}