//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

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)){
         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)}
   }
}