Centerfejl i java script

Kode 

var width=700;
var height=350;
var pause=3000;
var fade=100;

var fadeimages=new Array();

fadeimages[0]="test1.bmp";
fadeimages[1]="test2.bmp";
fadeimages[2]="test3.bmp";
fadeimages[3]="test4.bmp";
fadeimages[4]="test5.bmp";

function $(element) 
{
	if (typeof element == 'string')
	{
		var element = (document.getElementById ? document.getElementById(element) : (document.all ? document.all[element] : (document.layers ? document.layers[element] : null)));
	}
	return element;
}

function slideShow(hojde,bredde,pause,fade,billeder,id)
{
	if(!$(id)) return false;
	this.hojde = hojde;
	this.bredde = bredde;
	this.pause = pause;
	this.fade = fade;
	this.billeder = billeder;
	this.id = id;
	this.current = 0;
	this.canvas = 0;
	this.preLoad();
}

slideShow.prototype = {
	preLoad: function()
	{
		this.preloadedimages=new Array()
		for (p=0;p<this.billeder.length;p++)
		{
			this.preloadedimages[p]=new Image()
			this.preloadedimages[p].src=this.billeder[p]
		}
	},
	fadePic: function()
	{
		if(this.curpos<100)
		{
			this.curpos+=10
			if(this.tempobj.filters)
				this.tempobj.filters.alpha.opacity=this.curpos;
			else if(this.tempobj.style.opacity)
				this.tempobj.style.MozOpacity=this.curpos/100;
		}
		else
		{
			clearInterval(this.dropslide);
			this.tempobj=$(this.id+this.canvas);
			this.current=(this.current<=this.billeder.length)? this.current+1 : 0;
			this.tempobj.innerHTML='<img src="'+this.billeder[this.current]+'">';
			t=this;
			setTimeout("t.rotateImage()",this.pause);
		}
	},
	rotateImage: function()
	{
		t=this;
		this.resetIt();
		this.tempobj=$(this.id+this.canvas);
		this.tempobj.style.zIndex++;
		this.dropslide=setInterval("t.fadePic()",this.fade);
		this.canvas=(this.canvas=="0")? "1" : "0";
	},
	resetIt: function()
	{
		this.curpos=10;
		var crossobj=$(this.id+this.canvas)
		if (crossobj.filters)
			crossobj.filters.alpha.opacity=this.curpos
		else if (crossobj.style.MozOpacity)
			crossobj.style.opacity=this.curpos/100
	},
	start: function()
	{
		$(this.id).innerHTML = '<div style="width:'+this.bredde+';height:'+this.hojde+';overflow:hidden">'+
		'<div id="'+this.id+'canvas0" style="position:absolute;width:'+this.bredde+';height:'+this.hojde+';left:0;top:0;filter:alpha(opacity=10);opacity:0.1;">'+
		'<img src="'+this.billeder[this.current]+'"></div>'+
		'<div id="'+this.id+'canvas1" style="position:absolute;width:'+this.bredde+';height:'+this.hojde+';left:0;top:0;filter:alpha(opacity=10);opacity:0.1;"></div></div>';
		this.id+='canvas';
		this.rotateImage();
	}
}

window.onload=function(){
test = new slideShow(height,width,pause,fade,fadeimages,"dit id på elementet");
test.start();
}