var topMargin = 0;  
var slideTime = 1200;  
var ns6 = (!document.all && document.getElementById);  
var ie4 = (document.all);  
var ns4 = (document.layers);  

function layerObject(id,left) 
{
	if (ns6) 
	{  
		this.obj = document.getElementById(id).style;  
		this.obj.left = left;  
		return this.obj;  
	}  
	else if(ie4)
	{  
		this.obj = document.all[id].style;  
		this.obj.left = left;  
		return this.obj;  
	}  
	else if(ns4) 
	{  
		this.obj = document.layers[id];  
		this.obj.left = left;  
		return this.obj;  
	}  
}  

function layerSetup() 
{  
	floatLyr = new layerObject('publicidad_derecha', 1000);  
	window.setInterval("main()", 10)  
}  

function floatObject() 
{  
	if (ns4 || ns6) {  
		findHt = window.innerHeight;  
	} else if(ie4) {  
		findHt = document.body.clientHeight;  
	}  
}   

function main()
{  
	if (ns4)
	{  
		this.currentY = document.layers["publicidad_derecha"].top;  
		this.scrollTop = window.pageYOffset;  
		mainTrigger();  
	}  
	else if(ns6)
	{  
		this.currentY = parseInt(document.getElementById('publicidad_derecha').style.top);  
		this.scrollTop = scrollY;  
		mainTrigger();  
	}
	else if(ie4) 
	{  
		this.currentY = publicidad_derecha.style.pixelTop;  
		this.scrollTop = document.body.scrollTop;  
		mainTrigger();  
	}  
}  

function mainTrigger() 
{  
	var newTargetY = this.scrollTop + this.topMargin;  

	if ( this.currentY != newTargetY ) 
	{  
		if ( newTargetY != this.targetY ) 
		{  
			this.targetY = newTargetY;  
			floatStart();  
		}  

		animator();  
	}  
}  

function floatStart()
{  
	var now = new Date();  
	this.A = this.targetY - this.currentY;  
	this.B = Math.PI / ( 2 * this.slideTime );  
	this.C = now.getTime();  

	if (Math.abs(this.A) > this.findHt)
	{  
		this.D = this.A > 0 ? this.targetY - this.findHt : this.targetY + this.findHt;  
		this.A = this.A > 0 ? this.findHt : -this.findHt;  
	}  
	else
	{  
		this.D = this.currentY;  
	}  
}  

function animator() 
{  
	var now = new Date();  
	var newY = this.A * Math.sin( this.B * ( now.getTime() - this.C ) ) + this.D;  
	newY = Math.round(newY);  

	if (( this.A > 0 && newY > this.currentY ) || ( this.A < 0 && newY < this.currentY )) 
	{  
		if ( ie4 )document.all.publicidad_derecha.style.pixelTop = newY;  
		if ( ns4 )document.layers["publicidad_derecha"].top = newY;  
		if ( ns6 )document.getElementById('publicidad_derecha').style.top = newY + "px";  
	}  
}  

function start() 
{  
	if(screen.width>=1024 && screen.height>=768)
	{
		if(ns6||ns4) 
		{  
			pageWidth = innerWidth;  
			pageHeight = innerHeight;  
			layerSetup();  
			floatObject();  
		}  
		else if(ie4) 
		{  
			pageWidth = document.body.clientWidth;  
			pageHeight = document.body.clientHeight;  
			layerSetup();  
			floatObject();  
		}  
	}
	else
		if(typeof document.getElementById("publicidad_derecha") != "undefined")
                        document.getElementById('publicidad_derecha').innerHTML="";

}