//Drop Down/ Overlapping Content: http://www.dynamicdrive.com

//**Updated: Dec 19th, 07': Added ability to dynamically populate a Drop Down content using an external file (Ajax feature)

//**Updated: Feb 29th, 08':

                //1) Added ability to reveal drop down content via "click" of anchor link (instead of default "mouseover")

                //2) Added ability to disable drop down content from auto hiding when mouse rolls out of it

                //3) Added hidediv(id) public function to directly hide drop down div dynamically



//**Updated: Sept 11th, 08': Fixed bug whereby drop down content isn't revealed onClick of anchor in Safari/ Google Chrome



var dropdowncontent={

    disableanchorlink: true, //when user clicks on anchor link, should link itself be disabled (always true if "revealbehavior" above set to "click")

 hidedivmouseout: [true, 200], //Set hiding behavior within Drop Down DIV itself: [hide_div_onmouseover?, miliseconds_before_hiding]

    ajaxloadingmsg: "Loading content. Please wait...", //HTML to show while ajax page is being feched, if applicable

    ajaxbustcache: true, //Bust cache when fetching Ajax pages?



    getposOffset:function(what, offsettype){

        return (what.offsetParent)? what[offsettype]+this.getposOffset(what.offsetParent, offsettype) : what[offsettype]

    },



    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

    },



    show:function(anchorobj, subobj, e){

        if (!this.isContained(anchorobj, e) || (e && e.type=="click")){

            var e=window.event || e

            if (e.type=="click" && subobj.style.visibility=="visible"){

                subobj.style.visibility="hidden"

                return

            }

            var horizontaloffset=(subobj.dropposition[0]=="left")? -(subobj.offsetWidth-anchorobj.offsetWidth) : 0 //calculate user added horizontal offset

            var verticaloffset=(subobj.dropposition[1]=="top")? -subobj.offsetHeight : anchorobj.offsetHeight //calculate user added vertical offset

            subobj.style.left=this.getposOffset(anchorobj, "offsetLeft") + horizontaloffset + "px"

            subobj.style.top=this.getposOffset(anchorobj, "offsetTop")+verticaloffset+"px"

            subobj.style.clip=(subobj.dropposition[1]=="top")? "rect(auto auto auto 0)" : "rect(0 auto 0 0)" //hide drop down box initially via clipping

            subobj.style.visibility="visible"

            subobj.startTime=new Date().getTime()

            subobj.contentheight=parseInt(subobj.offsetHeight)

            if (typeof window["hidetimer_"+subobj.id]!="undefined") //clear timer that hides drop down box?

                clearTimeout(window["hidetimer_"+subobj.id])

            this.slideengine(subobj, (subobj.dropposition[1]=="top")? "up" : "down")

        }

    },



    curveincrement:function(percent){

        return (1-Math.cos(percent*Math.PI)) / 2 //return cos curve based value from a percentage input

    },



    slideengine:function(obj, direction){

        var elapsed=new Date().getTime()-obj.startTime //get time animation has run

        if (elapsed<obj.glidetime){ //if time run is less than specified length

            var distancepercent=(direction=="down")? this.curveincrement(elapsed/obj.glidetime) : 1-this.curveincrement(elapsed/obj.glidetime)

            var currentclip=(distancepercent*obj.contentheight)+"px"

            obj.style.clip=(direction=="down")? "rect(0 auto "+currentclip+" 0)" : "rect("+currentclip+" auto auto 0)"

            window["glidetimer_"+obj.id]=setTimeout(function(){dropdowncontent.slideengine(obj, direction)}, 10)

        }

        else{ //if animation finished

            obj.style.clip="rect(0 auto auto 0)"

        }

    },



    hide:function(activeobj, subobj, e){

        if (!dropdowncontent.isContained(activeobj, e)){

            window["hidetimer_"+subobj.id]=setTimeout(function(){

                subobj.style.visibility="hidden"

                subobj.style.left=subobj.style.top=0

                clearTimeout(window["glidetimer_"+subobj.id])

            }, dropdowncontent.hidedivmouseout[1])

        }

    },



    hidediv:function(subobjid){

        document.getElementById(subobjid).style.visibility="hidden"

    },



    ajaxconnect:function(pageurl, divId){

        var page_request = false

        var bustcacheparameter=""

        if (window.XMLHttpRequest) // if Mozilla, IE7, Safari etc

            page_request = new XMLHttpRequest()

        else if (window.ActiveXObject){ // if IE6 or below

            try {

            page_request = new ActiveXObject("Msxml2.XMLHTTP")

            } 

            catch (e){

                try{

                page_request = new ActiveXObject("Microsoft.XMLHTTP")

                }

                catch (e){}

            }

        }

        else

            return false

        document.getElementById(divId).innerHTML=this.ajaxloadingmsg //Display "fetching page message"

        page_request.onreadystatechange=function(){dropdowncontent.loadpage(page_request, divId)}

        if (this.ajaxbustcache) //if bust caching of external page

            bustcacheparameter=(pageurl.indexOf("?")!=-1)? "&"+new Date().getTime() : "?"+new Date().getTime()

        page_request.open('GET', pageurl+bustcacheparameter, true)

        page_request.send(null)

    },



    loadpage:function(page_request, divId){

        if (page_request.readyState == 4 && (page_request.status==200 || window.location.href.indexOf("http")==-1)){

            document.getElementById(divId).innerHTML=page_request.responseText

        }

    },



 init:function(anchorid, pos, glidetime, revealbehavior){

        var anchorobj=document.getElementById(anchorid)

        var subobj=document.getElementById(anchorobj.getAttribute("rel"))

        var subobjsource=anchorobj.getAttribute("rev")

        if (subobjsource!=null && subobjsource!="")

            this.ajaxconnect(subobjsource, anchorobj.getAttribute("rel"))

        subobj.dropposition=pos.split("-")

        subobj.glidetime=glidetime || 1000

        subobj.style.left=subobj.style.top=0

        if (typeof revealbehavior=="undefined" || revealbehavior=="mouseover"){

            anchorobj.onmouseover=function(e){dropdowncontent.show(this, subobj, e)}

            anchorobj.onmouseout=function(e){dropdowncontent.hide(subobj, subobj, e)}

            if (this.disableanchorlink) anchorobj.onclick=function(){return false}

        }

        else

            anchorobj.onclick=function(e){dropdowncontent.show(this, subobj, e); return false}

        if (this.hidedivmouseout[0]==true) //hide drop down DIV when mouse rolls out of it?

            subobj.onmouseout=function(e){dropdowncontent.hide(this, subobj, e)}

            

            

    }

    

}