//Animated Collapsible DIV- Author: Dynamic Drive (http://www.dynamicdrive.com)
//Last updated Aug 1st, 07'. Fixed bug with "block" parameter not working when persist is enabled
//Updated June 27th, 07'. Added ability for a DIV to be initially expanded.

var uniquepageid=window.location.href.replace("http://"+window.location.hostname, "").replace(window.location.search, "").replace(/^\//, ""); //get current page path and name, used to uniquely identify this page for persistence feature

function animatedcollapse(divId, animatetime, persistexpand, initstate, twinId){
	this.divId=divId;
	this.divObj=document.getElementById(divId);
	this.divObj.style.overflow="hidden";
	this.timelength=animatetime;
	this.initstate=(typeof initstate!="undefined" && initstate=="block")? "block" : "contract";
	this.isExpanded=animatedcollapse.getCookie(uniquepageid+"-"+divId); //"yes" or "no", based on cookie value
	if (this.isExpanded=="no") this.divObj.addClassName('notexpanded');
	this.contentheight=this.divObj.getHeight();
	var thisobj=this;
	if (isNaN(this.contentheight)){ //if no CSS "height" attribute explicitly defined, get DIV's height on window.load
		animatedcollapse.dotask(window, function(){thisobj._getheight(persistexpand)}, "load");
		if (!persistexpand && this.initstate=="contract" || persistexpand && this.isExpanded!="yes" && this.isExpanded!="") //Hide DIV (unless div should be expanded by default, OR persistence is enabled and this DIV should be expanded)
			this.divObj.style.display="none"; //hide content (versus collapse) until we can get its height
	}
	else if (!persistexpand && this.initstate=="contract" || persistexpand && this.isExpanded!="yes" && this.isExpanded!="") //Hide DIV (unless div should be expanded by default, OR persistence is enabled and this DIV should be expanded)
		this.divObj.style.height=0; //just collapse content if CSS "height" attribute available
	if (persistexpand) {
		animatedcollapse.dotask(window, function(){animatedcollapse.setCookie(uniquepageid+"-"+thisobj.divId, thisobj.isExpanded)}, "unload");
		this.persistexpand = persistexpand;
	}
	if (twinId) {
		this.twin = new animatedcollapse(twinId, animatetime, false, 'block');
	}
}

animatedcollapse.prototype._getheight=function(persistexpand){
	this.contentheight= this.divObj.getHeight();
	if (!persistexpand && this.initstate=="contract" || persistexpand && this.isExpanded!="yes"){ //Hide DIV (unless div should be expanded by default, OR persistence is enabled and this DIV should be expanded)
		this.divObj.style.height=0; //collapse content
		this.divObj.style.display="block";
	}
	else //else if persistence is enabled AND this content should be expanded, define its CSS height value so slideup() has something to work with
		this.divObj.style.height=this.contentheight+"px";
}
animatedcollapse.prototype.adjust=function(what){
	this.divObj.style.height='auto';
	this.contentheight = (what) ? parseInt(what) : this.divObj.getHeight();
}
animatedcollapse.prototype.update=function(what){
	this.contentheight = parseInt(what);
}

animatedcollapse.prototype._slideengine=function(direction){
	var elapsed=new Date().getTime()-this.startTime; //get time animation has run
	var thisobj=this;
	if (elapsed<this.timelength){ //if time run is less than specified length
		var distancepercent=(direction=="down")? animatedcollapse.curveincrement(elapsed/this.timelength) : 1-animatedcollapse.curveincrement(elapsed/this.timelength);
		this.divObj.style.height=parseInt(Math.round(distancepercent * this.contentheight)) +"px";
		if (this.twin) {
			this.twin.divObj.style.height = parseInt(Math.round((1 - distancepercent) * this.contentheight)) + 'px';
		}
		this.runtimer=setTimeout(function(){thisobj._slideengine(direction)}, 10);
	}
	else{ //if animation finished
		this.divObj.style.height=(direction=="down")? this.contentheight+"px" : "1px";
		this.isExpanded=(direction=="down")? "yes" : "no"; //remember whether content is expanded or not
		if (direction=="up") this.divObj.addClassName('notexpanded');
		this.runtimer=null;
		if (this.persistexpand) animatedcollapse.setCookie(uniquepageid+"-"+this.divId, this.isExpanded);
		if (direction=="down") this.divObj.style.height= "auto";//if height will change
		if (this.twin) {
			this.twin.divObj.style.height=(direction=="up")? this.twin.contentheight + "px" : "1px";
		}
	}
}


animatedcollapse.prototype.slidedown=function(){
	if (typeof this.runtimer=="undefined" || this.runtimer==null){ //if animation isn't already running or has stopped running
		if (isNaN(this.contentheight)) //if content height not available yet (until window.onload)
			alert("Please wait until document has fully loaded then click again");
		else if (this.isExpanded == "no"){ //if content is collapsed
			this.startTime=new Date().getTime(); //Set animation start time
			this.divObj.removeClassName('notexpanded');
			this._slideengine("down");
		}
	}
}

animatedcollapse.prototype.slideup=function(){
	if (typeof this.runtimer=="undefined" || this.runtimer==null){
		if (isNaN(this.contentheight))
			alert("Please wait until document has fully loaded then click again");
		else if (!this.isExpanded || this.isExpanded == "yes"){ //if content is expanded
			this.startTime=new Date().getTime();
			this._slideengine("up");
		}
	}
}

animatedcollapse.prototype.slideit=function(){
	this.isExpanded=animatedcollapse.getCookie(uniquepageid+"-"+this.divId)
	if (isNaN(this.contentheight))
		alert("Please wait until document has fully loaded then click again");
	else if ( this.isExpanded == "no") {
		this.slidedown();
		}
	else if ( !this.isExpanded || this.isExpanded == "yes") { //parseInt(this.divObj.style.height || this.divObj.getHeight())==this.contentheight
		this.slideup();
		}
}

// -------------------------------------------------------------------
// A few utility functions below:
// -------------------------------------------------------------------

animatedcollapse.curveincrement=function(percent){
	return (1-Math.cos(percent*Math.PI)) / 2; //return cos curve based value from a percentage input
}


animatedcollapse.dotask=function(target, functionref, tasktype){ //assign a function to execute to an event handler (ie: onunload)
	var tasktype=(window.addEventListener)? tasktype : "on"+tasktype;
	if (target.addEventListener)
		target.addEventListener(tasktype, functionref, false);
	else if (target.attachEvent)
		target.attachEvent(tasktype, functionref);
}

animatedcollapse.getCookie=function(Name){ 
	var re=new RegExp(Name+"=[^;]+", "i"); //construct RE to search for target name/value pair
	if (document.cookie.match(re)) //if cookie found
		return document.cookie.match(re)[0].split("=")[1]; //return its value
	return "";
}

animatedcollapse.setCookie=function(name, value){
	var expiredays = 14;
	var exdate=new Date();
	exdate.setDate(exdate.getDate()+expiredays);
	document.cookie= name+ "=" +escape(value)+
	((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
}