function ddpanel(setting) {
    setting.dir = "up" //initial state of panel (up="contracted")
    if (setting.stateconfig.persiststate  && ddpanel.getCookie(setting.ids[0]) == "down" ) {
        setting.dir = "down"
    }
    if (setting.dir == "up") { //if "up", output CSS to hide panel contents
        document.write('<style type="text/css">\n')
        document.write('#' + setting.ids[1] + '{height:' + parseInt(setting.stateconfig.initial) + 'px; overflow:hidden}\n')
        document.write('</style>\n')
    }
    setting.stateconfig.initial = parseInt(setting.stateconfig.initial)
    this.setting = setting
    if (setting.pointerimage.enabled) { //preload images
        var img1 = new Image(), img2 = new Image()
        img1.src = setting.pointerimage.src[0]
        img2.src = setting.pointerimage.src[1]
    }
    var thispanel = this
    if (window.addEventListener) //if non IE browsers, initialize panel window.onload
        ddpanel.addEvent(window, function (e) { thispanel.initpanel(setting) }, "load")
    else //else if IE, add 100 millisec after window.onload before initializing
        ddpanel.addEvent(window, function (e) { setTimeout(function () { thispanel.initpanel(setting) }, 100) }, "load")
    ddpanel.addEvent(window, function (e) { thispanel.uninit(setting) }, "unload")
}

ddpanel.events_array = [] //object array to contain events created by script

ddpanel.addEvent = function (target, functionref, tasktype) {
    var evtmodel = target.addEventListener ? "w3c" : "ie"
    var evtaction = evtmodel == "w3c" ? "addEventListener" : "attachEvent"
    var i = this.events_array.push({ //store event info in ddpanel.events_array[] and return current event's index within array
        target: target,
        tasktype: (evtmodel == "ie" ? "on" : "") + tasktype,
        listener: evtmodel == "ie" ? function () { return functionref.call(target, window.event) } : functionref
    }) - 1
    target[evtaction](this.events_array[i].tasktype, this.events_array[i].listener, evtmodel == "w3c" ? false : null)
}

ddpanel.removeEvent = function (target, functionref, tasktype) {
    var evtmodel = target.removeEventListener ? "w3c" : "ie"
    var evtaction = evtmodel == "w3c" ? "removeEventListener" : "detachEvent"
    target[evtaction](tasktype, functionref, evtmodel == "w3c" ? false : null)
}

ddpanel.getCookie = function (Name) {
    var re = new RegExp(Name + "=[^;]+", "i"); //construct RE to search for target name/value pair
    if (document.cookie.match(re)) //if cookie found
        return document.cookie.match(re)[0].split("=")[1] //return its value
    return null
}

ddpanel.setCookie = function (name, value) {
    document.cookie = name + "=" + value + ";path=/"
}

ddpanel.addpointer = function (target, className, imagesrc) {
    var pointer = document.createElement("img")
    pointer.src = imagesrc
    pointer.className = className
    pointer.style.borderWidth = 0
    target.appendChild(pointer)
    return pointer
}

ddpanel.prototype = {
    togglepanel: function (dir) { //public function that toggles the panel's state. Optional dir parameter ("up" or "down") to explicitly set state.

        var setting = this.setting
        setting.dir = dir || ((setting.dir == "up") ? "down" : "up")
        var pcontent = setting.pcontent, dir = setting.dir
        pcontent._currentheight = (dir == "down") ? pcontent._actualheight : setting.stateconfig.initial
        pcontent.style.height = pcontent._currentheight + "px"
        if (setting.pointerimage.enabled) {
            setting.arrow.src = setting.pointerimage.src[(setting.dir == "down") ? 1 : 0]
            setting.arrow.style.visibility = "visible"
        }
        ddpanel.setCookie(setting.ids[0], setting.dir)
    },

    togglepanelplus: function (dir) { //public function that toggles the panel's state w/ animation. Optional dir parameter ("up" or "down") to explicitly set state.
        var setting = this.setting
        setting.dir = dir || ((setting.dir == "up") ? "down" : "up")
        if (setting.pointerimage.enabled) {
            setting.arrow.style.visibility = "hidden"
        }
        clearTimeout(setting.revealtimer)
        this.revealcontent()
    },

    revealcontent: function () {
        var setting = this.setting
        var pcontent = setting.pcontent, curH = pcontent._currentheight, maxH = pcontent._actualheight, minH = setting.stateconfig.initial, steps = setting.animate.steps, dir = setting.dir
        if (dir == "down" && curH < maxH || dir == "up" && curH > minH) {
            var newH = curH + (Math.round((maxH - curH) / steps) + 1) * (dir == "up" ? -1 : 1)
            newH = (dir == "down") ? Math.min(maxH, newH) : Math.max(minH, newH)
            pcontent.style.height = newH + "px"
            pcontent._currentheight = newH
        }
        else {
            if (setting.pointerimage.enabled) {
                setting.arrow.src = setting.pointerimage.src[(setting.dir == "down") ? 1 : 0]
                setting.arrow.style.visibility = "visible"
            }
            return
        }
        var thispanel = this
        setting.revealtimer = setTimeout(function () { thispanel.revealcontent() }, 10)
    },

    initpanel: function () {
        var setting = this.setting
        var pcontainer = setting.pcontainer = document.getElementById(setting.ids[0])
        var pcontent = setting.pcontent = document.getElementById(setting.ids[1])
        var tdiv = setting.tdiv = document.getElementById(setting.ids[2])
        pcontent.style.overflow = "scroll"
        pcontent._actualheight = pcontent.scrollHeight
        setTimeout(function () { pcontent._actualheight = pcontent.scrollHeight }, 100)
        pcontent.style.overflow = "hidden"

        pcontent.style.lineHeight = "0px";
        pcontent.style.fontSize = "1px";


        pcontent._currentheight = (setting.dir == "down") ? pcontent._actualheight : setting.stateconfig.initial
        var thispanel = this
        ddpanel.addEvent(tdiv, function (e) { //assign click behavior when toggle DIV tab is clicked on
            if (setting.animate.enabled)
                thispanel.togglepanelplus()
            else
                thispanel.togglepanel()
            if (e.preventDefault) e.preventDefault()
            return false
        }, "click")
        if (setting.pointerimage.enabled) {
            var pointer1 = new Image(), pointer2 = new Image()
            pointer1.src = setting.pointerimage.src[0]
            pointer2.src = setting.pointerimage.src[1]
            setting.arrow = ddpanel.addpointer(tdiv.getElementsByTagName("span")[0], "pointerimage", setting.pointerimage.src[setting.dir == "down" ? 1 : 0])
        }
        if (setting.closepanelonclick.enabled) { //assign click behavior when panel content is clicked on (links within panel or elements with class "closepanel"
            ddpanel.addEvent(pcontent, function (e) {
                var target = e.srcElement || e.target
                if (/(^|\s+)closepanel($|\s+)/.test(target.className) || target.tagName == "A" || (target.parentNode && target.parentNode.tagName == "A")) {
                    thispanel.togglepanel("up")
                }
            }, "click")
        }
    },

    uninit: function () {
        var setting = this.setting
        if (setting.stateconfig.persiststate) {
            ddpanel.setCookie(setting.ids[0], setting.dir)
        }
        for (prop in setting) {
            setting[prop] = null
        }
    }



} //end of ddpanel object


//initialize instance of DD Drop Down Panel:

var defaultpanel = new ddpanel({
    ids: ["mypanel", "mypanelcontent", "mypaneltab"], // id of main panel DIV, content DIV, and tab DIV
    stateconfig: { initial: "0", persiststate: false }, // initial: initial reveal amount in pixels (ie: 5px)
    animate: { enabled: true, steps: 5 }, //steps: number of animation steps. Int between 1-20. Smaller=faster.
    pointerimage: { enabled: true, src: ["/fileSystem/skin/KernaRedV2/images/arrow-down.gif", "/fileSystem/skin/KernaRedV2/images/arrow-up.gif"] },
    closepanelonclick: { enabled: false} // close panel when links or elements with CSS class="closepanel" within container is clicked on?
})