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++)

                {

                               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._newfade();

}

 

_bsn.Crossfader.prototype._newfade = function()

{

                if (this.nID1)

                               clearInterval(this.nID1);

                

                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;

}