//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
//**Updated: April 9th, 10': Minor change

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)
                if (anchorobj)
                        var subobj=document.getElementById(anchorobj.getAttribute("rel"))
                if (!anchorobj || !subobj)
                        return
                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)}
        }
}