/**
 *  author:		Timothy Groves - http://www.brandspankingnew.net
 *	version:	1.3 - 2006-11-02
 *				1.2 - 2006-11-01
 *				1.1 - 2006-09-29
 *				1.0 - 2006-09-25
 *
 *	requires:	nothing
 *
 */

var useBSNns;

if (useBSNns)
{
	if (typeof(bsn) == "undefined")
		bsn = {}
	var _bsn = bsn;
}
else
{
	var _bsn = this;
}


_bsn.Crossfader = function (divs, fadetime, delay )
{	
	this.nAct = -1;
	this.aDivs = divs;
	
	for (var i=0;i<divs.length;i++){
		this._adjustdivs(divs[i],0,1);
	}
	
	this.nDur = fadetime;
	this.nDelay = delay;
	this.bPlay = 1;
	this.queue=-1;
	this.nDelayCnt=0;
	var p=this;
	this.nID1 = setInterval(function() { p._timer() }, this.nDelay/100);
	this._newfade();
}

_bsn.Crossfader.prototype._adjustdivs = function(id, ieop,init)
{
		this._adjustdiv(document.getElementById(id), ieop,init);
		if (init){
			document.getElementById(id).style.position = "absolute";
			document.getElementById(id).style.visibility = "hidden";
		}
		
		var subdivs = document.getElementById(id).getElementsByTagName('div');
		for (var x=0;x<subdivs.length;x++){
			if (!subdivs[x].name){
				this._adjustdiv(subdivs[x], ieop,init);
			}else{
			 	if (subdivs[x].name != 'nofollow'){
					this._adjustdiv(subdivs[x], ieop,init);
			 	}
			}
		}
}

_bsn.Crossfader.prototype._adjustdiv = function(d,ieop,init)
{
	var op = ieop / 100;
	if (ieop<100){
		d.style.opacity = op;
		d.style.filter = "alpha(opacity="+ieop+")";
	}else{
		if(d.style.removeAttribute){
			d.style.removeAttribute('opacity');
			d.style.removeAttribute('filter');
		}else{
			d.style.opacity = 1;
			d.style.filter = "alpha(opacity=100)";
		}
	}
}

_bsn.Crossfader.prototype._timer = function()
{
	if (this.bPlay) this.nDelayCnt++;
	if (this.nDelayCnt>100 &&  !this.fading){
		this._newfade();	
	}
}

_bsn.Crossfader.prototype._selectfade = function(idx)   // added by Ben
{
		this.queue=idx;
		this.nDelayCnt=101;
		this.bPlay=0;
}

_bsn.Crossfader.prototype._newfade = function()
{
	//if (this.nID1)
		//clearInterval(this.nID1);
	this.nDelayCnt=0;
	
	this.nOldAct = this.nAct;
	this.nAct++;
	if (this.queue > -1){
		this.nAct=this.queue;
		this.queue=-1;
	}
	
	if (!this.aDivs[this.nAct])	this.nAct = 0;
	
	if (this.nAct == this.nOldAct)
		return false;
	
	document.getElementById( this.aDivs[this.nAct] ).style.visibility = "visible";
	
	this.nInt = 50;
	this.nTime = 0;
	var p=this;
	this.fading=1;
	this.nID2 = setInterval(function() { p._fade() }, this.nInt);
}


_bsn.Crossfader.prototype._play = function()    // added by Ben
{
	this.bPlay=1;
	this.nDelayCnt=100;
}

_bsn.Crossfader.prototype._fade = function()
{
	this.nTime += this.nInt;
	
	var ieop = Math.round( this._easeInOut(this.nTime, 0, 1, this.nDur) * 100 );
//	var op = ieop / 100;
//	document.getElementById( this.aDivs[this.nAct] ).style.opacity = op;
//	document.getElementById( this.aDivs[this.nAct] ).style.filter = "alpha(opacity="+ieop+")";
	this._adjustdivs(this.aDivs[this.nAct] , ieop);
	
	if (this.nOldAct > -1)
	{
		//document.getElementById( this.aDivs[this.nOldAct] ).style.opacity = 1 - op;
		//document.getElementById( this.aDivs[this.nOldAct] ).style.filter = "alpha(opacity="+(100 - ieop)+")";
		this._adjustdivs(this.aDivs[this.nOldAct] ,100-ieop);

	}
	
	if (this.nTime >= this.nDur)
	{
		clearInterval( this.nID2 );
		this.fading=0;
		
		if (this.nOldAct > -1)
			document.getElementById( this.aDivs[this.nOldAct] ).style.visibility = "hidden";	
		
		if (this.queue>-1){
			this._selectfade(this.queue);
			this.queue=-1;
		}
		
		var p=this;
		this.nDelayCnt=0;
	}
}



_bsn.Crossfader.prototype._easeInOut = function(t,b,c,d)
{
	return c/2 * (1 - Math.cos(Math.PI*t/d)) + b;
}