OOP - gallery.Play() is not a function

[MRj92]

salve ragazzi!

Ho bisogno di voi perchè non mi capisco!

Ho creato la seguente classa javascript:

function EmarGallery(id,numStart)
{
this.id = id;
this.numStart = numStart;
this.images = null;
this.interval = null;
this.OpacityIn = 0;
this.IntervalIn = null;
this.OpacityOut = 1;
this.IntervalOut = null;
this.current = null;
this.prec = null;

this.Load = function()
{
gallery = document.getElementById(this.id);
		
	if(gallery != null)
	{
		this.images = new Array();
		var node = gallery.firstChild;

		while(node)
		{
			if (node.nodeType == 1)
			{
				this.images.push(node);
			}
			node = node.nextSibling;
		}
		alert("loaded!");

	}
};
this.ChangeImg = function(arg)
{
	this.prec = this.current;

	if(arg > (this.images.length-1)) this.current = 0;
	else if(0 > arg) this.current = this.images.length-1;
	else this.current = arg;

	if(this.images[this.prec] != null)
	{
		//IntervalIn = setInterval('this.FadeOut(this.images[this.prec])',1);
		this.images[this.prec].style.display = 'none';
		this.setOpacity(this.images[this.prec],0);
	}
	this.images[this.current].style.display = 'block';
	//this.images[this.current].style.left = Math.floor(Math.random()*300);
	this.IntervalIn = setInterval('this.FadeIn(this.images[this.current])',1);
};
this.ChangeRand = function()
{
	var num;
	
	do{
	num = Math.floor(Math.random()*images.length);
	}while(num == this.current || num == this.prec)
	

	this.ChangeImg(num);
};
this.Play = function(sec,rand)
{
		if(rand != true)
		{
			if(this.numStart != null) this.ChangeImg(this.numStart);
			else this.ChangeImg(0);

			if(this.images.length != 1)
			{
			this.interval = setInterval('this.ChangeImg(this.current+1)',sec*1000);
			}
		}
		else{
			if(this.numStart != null) this.ChangeImg(this.numStart);
			else this.ChangeRand();

			if(this.images.length != 1)
			{
			this.interval = setInterval('this.ChangeRand()',sec*1000);
			}
		}
};
this.Stop = function()
{
	clearInterval(this.interval);
};
this.setOpacity = function(obj,value)
{
	if(obj.style.filter != null) obj.style.filter = 'alpha(opacity=' + value*100 + ')';
	else if(obj.filters != null) obj.filters.alpha.opacity = value*100;
	else obj.style.opacity = value;
};
this.FadeIn = function(obj)
{
	if(this.OpacityIn >= 1)
	{
		clearInterval(this.IntervalIn);
		this.IntervalIn = null;
		this.OpacityIn = 0;
	}
	else
	{
	this.OpacityIn = this.OpacityIn + 0.05;
	this.setOpacity(obj,this.OpacityIn);
	}
};
this.FadeOut = function(obj)
{
	if(this.OpacityOut <= 0)
	{
		clearInterval(this.IntervalOut);
		this.IntervalOut = null;
		this.OpacityOut = 1;
	}
	else
	{
	this.OpacityOut = this.OpacityOut - 0.05;
	this.setOpacity(obj,this.OpacityOut);
	}
};
};

poi ho questo file:

var gallery = new EmarGallery("PortfolioGallery",0);

window.onload = function()
{
	LoadMenu();
	externalLinks();
	gallery.Load();
	gallery.Play(4,true);
}

window.onunload = function()
{
	gallery.Stop();
}

dove mi da i seguenti errori:

• gallery.Play is not a function
• gallery.Stop is not a function

La cosa che mi fa incazzare è che non capisco perchè gallery.Load() funziona!