//Drop Down/ Overlapping Content: http://www.dynamicdrive.com
//Last updated: Dec 19th, 07': Added ability to dynamically populate a Drop Down content using an external file (Ajax feature)

var dropdowncontent = {
  disableanchorlink: true, //when user clicks on anchor link, should it be disabled?
  ajaxloadingmsg: "Loading content. Please wait...", //HTML to show while ajax page is being feched
  ajaxbustcache: true, //Bust cache when fetching 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
    if (m.onmouseover){
     var c=e.relatedTarget || ((e.type=="mouseover")? e.fromElement : e.toElement)
    }else{
     var c=e.relatedTarget || ((e.type=="mouseup")? 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)){
      if (anchorobj.onmouseover){
       var horizontaloffset=(subobj.dropposition[0]=="left")? -(subobj.offsetWidth-anchorobj.offsetWidth) : 100 //calculate user added horizontal offset
       var verticaloffset=(subobj.dropposition[1]=="top")? -(subobj.offsetHeight-anchorobj.offsetHeight) : 30 //calculate user added vertical offset
      }else{
       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])
        }, activeobj.delay)
      }
    },

    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
      }
    },

     initDropDown:function(anchorid, pos, glidetime, anchor_type){
      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;
      subobj.delay = (anchor_type == "mouseover") ? 0 : 200
      if(anchor_type == "mouseover"){
       anchorobj.onmouseover = function(e) { dropdowncontent.show(this, subobj, e) };
      }else{
       anchorobj.onmouseup = function(e) { dropdowncontent.show(this, subobj, e) };
      }
      anchorobj.onmouseout = function(e) { dropdowncontent.hide(subobj, subobj, e) };
      if (this.disableanchorlink) { anchorobj.onclick = function(){return false} };
      subobj.onmouseout = function(e){ dropdowncontent.hide(this, subobj, e) };
    }
  }