NS4 = (document.layers);
IE4 = (document.all);
var scrollTim;
var active = 0;
timSpeed=1

function makeScrollObj(obj,nest){
	nest=(!nest) ? '':'document.'+nest+'.'
	this.css=(NS4) ? eval(nest+'document.'+obj):eval('document.all.'+obj+'.style')
	this.scrollHeight=NS4?this.css.document.height:eval('document.all.'+obj+'.offsetHeight')
	this.top=b_gettop
	return this
}

function b_gettop(){
	var gleft=(NS4) ? eval(this.css.top):eval(this.css.pixelTop);
	return gleft;
}

function scroll(speed,contHeight){
	clearTimeout(scrollTim)
	way=speed>0?1:0
	if((!way && oScroll[active].top()>-oScroll[active].scrollHeight+contHeight) || (oScroll[active].top()<0 && way)){
		oScroll[active].css.top=oScroll[active].top()+speed
		scrollTim=setTimeout("scroll("+speed+","+contHeight+")",timSpeed)
	}
	window.focus()
}

function inicio(){
	oScroll[active].css.top=0;
	window.focus()
}

function fin(contHeight){
	 oScroll[active].css.top=(-(oScroll[active].scrollHeight)+contHeight);
	 window.focus()
}

function noScroll(){
	clearTimeout(scrollTim)
}

function scrollInit(){
	oScroll=new Array()
	oScroll[0]=new	makeScrollObj('layerDescripcion','divCont')	
}