function ItemsScroller() {
	var posMin = 0,
		posMax = 5,
		arrIds = [];

	this.add = function(id) {
		arrIds.push(id);
	}

	this.setPosMax = function(max) {
		posMax = max;
	}

	this.show = function() {
		var lmnt, j;
		for (j = 0; j < arrIds.length; ++j) {
			lmnt = document.getElementById(arrIds[j]);
			if (lmnt) {
				/* Oculto|muestro el nodo */
				lmnt.style.display = ((j < posMin || j >= posMax)? "none": "");
			}
		}
	}

	this.prev = function() {
		if (posMin > 0) {
			--posMax;
			--posMin;
			this.show();
		}
	}

	this.next = function() {
		if (posMax < arrIds.length) {
			++posMax;
			++posMin;
			this.show();
		}
	}
}