var clipTop = 0;
var clipWidth = 405;
var clipBottom = 100;
var topper = 131;
var lyrheight = 5;
var time,amount,theTime,theHeight,DHTML;

var inicial;
var velocidad;


function init()
{
	DHTML = (document.getElementById || document.all || document.layers)
	if (!DHTML) {return};

 if (navigator.appName == "Netscape")
	{
	velocidad = 2;
	}
else if (navigator.appName.indexOf("Explorer") != -1) 
	{
	velocidad = 25;
	} 
else
	{
	velocidad = 10;
	} 

	var x = new getObj('example');
	if (document.layers)
	{
		lyrheight = x.style.clip.bottom;
		inicial = x.style.clip.bottom;
		lyrheight += 20;
		x.style.clip.top = clipTop;
		x.style.clip.left = 0;
		x.style.clip.right = clipWidth;
		x.style.clip.bottom = clipBottom;
	}
	else if (document.getElementById || document.all)
	{
		lyrheight = x.obj.offsetHeight;
		inicial = x.obj.offsetHeight;
		x.style.clip = 'rect('+clipTop+' '+clipWidth+' '+clipBottom+' 0)'
	}
}

function scrollayer(layername,amt,tim)
{
	if (!DHTML) return;
	thelayer = new getObj(layername);
	if (!thelayer) return;
	amount = amt;
	theTime = tim;
	realscroll();
	
	//document.getElementById('mostrar').value+="topper:"+topper+" clipBottom:"+clipBottom+" clipTop:"+clipTop+" lyrheight:"+lyrheight+" alto:"+thelayer.style.height+"\n";

}

function reiniciar()
{	
		 clipTop = 0;
		 topper = 131;
		 clipBottom = 100;
	lyrheight = inicial;
	
	var x = new getObj('example');
	if (document.layers)
	{
		
		x.style.clip.top = clipTop;
		x.style.clip.left = 0;
		x.style.clip.right = clipWidth;
		x.style.clip.bottom = clipBottom;
	}
	else if (document.getElementById || document.all)
	{
		
		x.style.clip = 'rect('+clipTop+' '+clipWidth+' '+clipBottom+' 0)'
	}
	
	//document.getElementById('mostrar').value+="topper:"+topper+" clipBottom:"+clipBottom+" clipTop:"+clipTop+" lyrheight:"+lyrheight+" alto:"+thelayer.style.height+"\n";
	
	
}

function realscroll()
{
	if (!DHTML) return;
	clipTop += amount;
	clipBottom += amount;
	topper -= amount;
	
	
	
	if (clipTop < 0 || clipBottom > lyrheight)
	{
		
		clipTop -= amount;
		clipBottom -= amount;
		topper += amount;
		return;
	}
	if (document.getElementById || document.all)
	{
		clipstring = 'rect('+clipTop+' '+clipWidth+' '+clipBottom+' 0)'
		thelayer.style.clip = clipstring;
		thelayer.style.top = topper;
		

	}
	else if (document.layers)
	{
		thelayer.style.clip.top = clipTop;
		thelayer.style.clip.bottom = clipBottom;
		thelayer.style.top = topper;
	}
	time = setTimeout('realscroll()',theTime);
	if (clipBottom==lyrheight)
	{reiniciar();}
}

function stopScroll()
{
	if (time) clearTimeout(time);
}
function getObj(name)
{
  if (document.getElementById)
  {
  	this.obj = document.getElementById(name);
	this.style = document.getElementById(name).style;
  }
  else if (document.all)
  {
	this.obj = document.all[name];
	this.style = document.all[name].style;
  }
  else if (document.layers)
  {
   	this.obj = document.layers[name];
   	this.style = document.layers[name];
  }
}