//Animated Collapsible DIV- Author: Dynamic Drive (http://www.dynamicdrive.com)
//Last updated June 27th, 07'. Added ability for a DIV to be initially expanded.

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

function animatedcollapse(divId, animatetime, persistexpand, initstate){
	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
	this.contentheight=parseInt(this.divObj.style.height,10);
	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")
		{ //Hide DIV (unless div should be expanded by default, OR persistence is enabled and this DIV should be expanded)
			this.divObj.style.visibility="hidden"; //hide content (versus collapse) until we can get its height
		}
	}
	else 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; //just collapse content if CSS "height" attribute available
	}
	if (persistexpand)
	{
		animatedcollapse.dotask(window, function(){animatedcollapse.setCookie(uniquepageid+"-"+thisobj.divId, thisobj.isExpanded);}, "unload");
	}
}

animatedcollapse.prototype._getheight=function(persistexpand){
	this.contentheight=this.divObj.offsetHeight;
	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.visibility="visible";
	}
	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._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=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" : 0;
		this.isExpanded=(direction=="down")? "yes" : "no"; //remember whether content is expanded or not
		this.runtimer=null;
	}
};


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 (parseInt(this.divObj.style.height,10)===0)
		{ //if content is collapsed
			this.startTime=new Date().getTime(); //Set animation start time
			this._slideengine("down");
		}
	}
};

animatedcollapse.prototype.slideup=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 (parseInt(this.divObj.style.height,10)==this.contentheight)
		{ //if content is expanded
			this.startTime=new Date().getTime();
			this._slideengine("up");
		}
	}
};

animatedcollapse.prototype.slideit=function()
{
	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 (parseInt(this.divObj.style.height,10)===0)
	{
		this.slidedown();
	}
	else if (parseInt(this.divObj.style.height,10)==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 tasktyper=(window.addEventListener)? tasktype : "on"+tasktype;
	if (target.addEventListener)
	{
		target.addEventListener(tasktyper, functionref, false);
	}
	else if (target.attachEvent)
	{
		target.attachEvent(tasktyper, 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, days){
	if (typeof days!="undefined")
	{ //if set persistent cookie
		var expireDate = new Date();
		var expstring=expireDate.setDate(expireDate.getDate()+days);
		document.cookie = name+"="+value+"; expires="+expireDate.toGMTString();
	}
	else
	{ //else if this is a session only cookie
		document.cookie = name+"="+value;
	}
};