function muestraTrabajoGaleria(id) {
	var divs = $('scrollObjetivoGaleria').getElementsByTagName('DIV');
	divs[id*2].style.visibility = 'visible';
}
function ocultaTrabajoGaleria(id) {
	var divs = $('scrollObjetivoGaleria').getElementsByTagName('DIV');
	divs[id*2].style.visibility = 'hidden';
}

function changeImage(src, alt, w) {
	var l = $('loading');
	l.src = src;
	l.alt = alt;
	l.onload = function() {
		l.className = '';
		if (l.width > w) {
			l.height = l.height * w / l.width;
			l.width = w;
		}
		if (l.height > 370) {
			l.width = l.width * 370 / l.height;
			l.height = 370;
		}
		if (l.height < 370) {
			var m = (370-l.height)/2;
			l.style.marginTop = m+'px';
		}
		l.parentNode.href = $('ampliar').href;
		l.parentNode.title = alt;
	}
}

var Scroller = new Class({
	options: {
		mySlider : Class.empty
	},
	initialize: function(carril, barra, objetivo)
	{
		this.carril = carril;
		this.barra = barra;
		this.objetivo = objetivo;
		
		var alto = objetivo.clientHeight;
		objetivo.style.height = 'auto';
		var todo2 = objetivo.scrollHeight;
		objetivo.style.height = alto + 'px';
		
		var todo = objetivo.scrollHeight;
		var visible = objetivo.offsetHeight;
		var paso = (todo - visible) / 100;
		
		if (todo > alto)
			barra.style.height = visible * carril.clientHeight / todo2 + 'px';
		else
			barra.style.display = 'none';
		
		this.options.mySlider = new Slider(carril, barra, {	
			steps: 100,	
			mode: 'vertical',	
			onChange: function(step) {
				objetivo.scrollTop = paso * step;
			}
		}).set(0);
	},
	up: function() {
		this.options.mySlider.set( this.options.mySlider.step - 10 );
	},
	down: function() {
		this.options.mySlider.set( this.options.mySlider.step + 10 );
	},
	to: function(pos) {
		this.options.mySlider.set( pos );
	}
});

var Scroller2 = new Class({
	options: {
		mySlider : Class.empty
	},
	initialize: function(carril, barra, objetivo)
	{
		this.carril = carril;
		this.barra = barra;
		this.objetivo = objetivo;
		
		var alto = objetivo.clientHeight;
		objetivo.style.height = 'auto';
		var todo2 = objetivo.scrollHeight;
		objetivo.style.height = alto + 'px';
		
		var todo = objetivo.scrollHeight;
		var visible = objetivo.offsetHeight;
		var paso = (todo - visible) / 100;
		
		if (todo > alto)
			barra.style.height = visible * carril.clientHeight / todo2 + 'px';
		else
			barra.style.display = 'none';
		
		this.options.mySlider = new Slider(carril, barra, {	
			steps: 100,	
			mode: 'vertical',	
			onChange: function(step) {
				objetivo.scrollTop = paso * step;
			}
		}).set(0);
	},
	up: function() {
		this.options.mySlider.set( this.options.mySlider.step - 10 );
	},
	down: function() {
		this.options.mySlider.set( this.options.mySlider.step + 10 );
	},
	to: function(pos) {
		this.options.mySlider.set( pos );
	}
});