//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)}
}
}