/**
 *  author:		Timothy Groves - http://www.brandspankingnew.net/archive/2006/09/javascript_css_crossfader.html
 *	version:	1.3 - 2006-11-02
 *				1.2 - 2006-11-01
 *				1.1 - 2006-09-29
 *				1.0 - 2006-09-25
 *	requires:	nothing  
* 2008-09-13 menge webdesign  -  http://www.menge-webdesign.nl/nl/toys/javascript/crossfader
* onload listener instead of al the onload stuff from Gregory Smith 
*/
window.addEventListener?window.addEventListener("load",LoadedCF,false):window.attachEvent("onload",LoadedCF);
/*
* below is from Timothty Groves and Gregory Smith
* I don't dare to touch it, since it works like a charm and I ain't no javascript programmer
*/
var useBSNns;
if (useBSNns) {
	if (typeof(bsn) == "undefined")
		bsn = {}
	var _bsn = bsn;
} else { 	var _bsn = this; }
// Constructor
_bsn.Crossfader = function (divs, fadetime, delay ) {	
	this.nAct = -1;
	this.aDivs = divs;
	for (var i=0;i<divs.length;i++)	{
		document.getElementById(divs[i]).style.opacity = 0;
		document.getElementById(divs[i]).style.position = "absolute";
		document.getElementById(divs[i]).style.filter = "alpha(opacity=0)";
		document.getElementById(divs[i]).style.visibility = "hidden";
	}
	this.nDur = fadetime;
	this.nDelay = delay;
	this.stopPending = false;
	this.stopped = false;
	this._newfade();
}
// Public methods
_bsn.Crossfader.prototype.StopFade = function() {
	if (this.stopped || this.stopPending) { return; }
	this.stopPending = true;
	//if (this.nID1)
	//	clearInterval(this.nID1);
}

_bsn.Crossfader.prototype.StartFade = function() {
	if (this.stopPending) {
		this.stopPending = false; // Cancel pending stop
		return;
	}
	else if (!this.stopped) { return; }
	this._newfade();
}
_bsn.Crossfader.prototype.SetFade = function(newFade) {
	newFade = parseFloat(newFade);
	if (isNaN(newFade)) { 	return "Value provided for new fade time must be numeric"; }
	if (newFade < 0) { return "Value provided for new fade time cannot be negative"; }
	this.StopFade();
	this.nDur = newFade * 1000;
	this.StartFade();
	return "";
}
_bsn.Crossfader.prototype.SetDelay = function(newDelay) {
	newDelay = parseFloat(newDelay);
	if (isNaN(newDelay)) { return "Value provided for new display time must be numeric"; 	}
	if (newDelay <= 0) 	{ return "Value provided for new display time must be greater than zero"; }
	this.StopFade();
	this.nDelay = newDelay * 1000;
	this.StartFade();
	return "";
}
// Private methods
_bsn.Crossfader.prototype._newfade = function() {
	if (this.nID1)
		clearInterval(this.nID1);
	if (this.stopPending) {
		this.stopPending = false;
		this.stopped = true;
		return;
	}
	this.stopped = false;
	this.nOldAct = this.nAct;
	this.nAct++;
	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.nID2 = setInterval(function() { p._fade() }, this.nInt);
}
_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+")";
	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)+")";
	}
	if (this.nTime == this.nDur) {
		clearInterval( this.nID2 );
		if (this.nOldAct > -1)
			document.getElementById( this.aDivs[this.nOldAct] ).style.visibility = "hidden";	
		var p=this;
		this.nID1 = setInterval(function() { p._newfade() }, this.nDelay);
	}
}
_bsn.Crossfader.prototype._easeInOut = function(t,b,c,d) {
	return c/2 * (1 - Math.cos(Math.PI*t/d)) + b;
}
/*
 * Some wrapper code for Timothy Groves's Crossfader (http://www.brandspankingnew.net/archive/2006/09/javascript_css_crossfader.html)
 * Code in this wrapper is tied closely to the HTML page (e.g., div and button id's are hard-coded).  There's
 * also some Javascript embedded with the HTML so it gets executed as the page is loaded -- helps the slide
 * show to degrade gracefully if the user doesn't have JS enabled.
 * Gregory Smith
 * http://beaglewriter.com
 * beaglewriter@att.net
 
* 2008-09-13 menge webdesign  -   http://www.menge-webdesign.nl/nl/toys/javascript/crossfader
* almost deleted everything from the wrappercode, since the intention only was to create a mouseover mouseout effect.
* there was also a whole bunch of code to detect which div was fading or not, and if so or not, the div would stop or go onclick
* however that only worked onmouseover, onmouseout half of the time
* my guess was that the script was not always sure which div to start or to stop, so I put that stuff in the div itself with a simple onmouseover="StopCF();" and
* of course onmouseout="StartCF();"
* Finally I thought it was more handy to put the time vars in the head, so I can use this script without altering.
*/
function LoadedCF() { cf = new Crossfader(divsToFade, fadetime, fadedelay); }
function StopCF(e) { cf.StopFade(); }
function StartCF(e) { cf.StartFade(); }