/*	DHTML */
function getStyleById(id, style)
{
	var elm = document.getElementById(id);
	return getStyle(elm, style);
};
function getStyle(elm, style)
{
	if(typeof(document.defaultView) == 'object') return document.defaultView.getComputedStyle(elm, null).getPropertyValue(style);
	else if(elm.currentStyle) return elm.currentStyle[style];
};
function setStyleById(id, style, value)
{
	var elm = document.getElementById(id);
	setStyle(elm, style, value);
};
function setStyle(elm, style, value)
{
	elm.style[style] = value;
};
/*	Rollovers */
function RollInit()
{
	var imgs = document.getElementsByTagName('IMG');
	for(var i = 0; i != imgs.length; ++i) {
		if(/(\w+)ROLL$/.test(imgs[i].id)) {
			var roll_id = RegExp.$1;
			if(/(\w+)FOTO$/.test(roll_id)) {
				// ...
			} else {
				var elm = imgs[i];
				elm.img_over = new Image();
				elm.img_over.src = elm.src.replace(/(.gif|.jpg|.png)$/, '_over$1');
				elm.img_orig = new Image();
				elm.img_orig.src = elm.src;
				if(/(\w+)MENU$/.test(roll_id)) {
					elm.MyRollOver = RollOver;
					elm.MyRollOut = RollOut;
				} else {
					elm.onmouseover = RollOver;
					elm.onmouseout = RollOut;
				}
			}
		}
	}
};
function RollOver()
{
	this.src = this.img_over.src;
};
function RollOut()
{
	this.src = this.img_orig.src;
};

/*	Layer Opacities and Blends (cross-browser) */
function setOpacityById(id, alfa)
{
	var elm = document.getElementById(id);
	return setOpacity(elm, alfa);
};
function setOpacity(elm, alfa)
{
	if(alfa == 0) {
		elm.style.visibility = 'hidden';
	} else if(elm.style.visibility == 'hidden') {
		elm.style.visibility = 'inherit';
	}
	if(typeof(elm.style.opacity) != 'undefined') elm.style.opacity = (alfa == 1) ? '0.999' : alfa;
	else if(typeof(elm.style.filter) != 'undefined') elm.style.filter = (alfa == 1) ? '' : 'alpha(opacity=' + (alfa*100) + ')';
	else if(typeof(elm.style.MozOpacity) != 'undefined') elm.style.MozOpacity = (alfa == 1) ? '0.999' : alfa;
	else if(typeof(elm.style.KhtmlOpacity) != 'undefined') elm.style.KhtmlOpacity = alfa;
};
function BlendById(id, alfa0, alfa1)
{
	var elm = document.getElementById(id);
	return Blend(elm, alfa0, alfa1);
};
var blend_elm = null;
var blend_alfa1 = 0;
var blend_tmr = null;
var blend_t = 50;
function Blend(elm, alfa0, alfa1)
{
	if(blend_tmr) {
		clearTimeout(blend_tmr);
		blend_tmr = null;
	}
	if(blend_elm) {
		setOpacity(blend_elm, blend_alfa1);
	}
	blend_elm = elm;
	blend_alfa1 = alfa1;
	blend_tmr = setTimeout('cicloBlend(' + alfa0 + ')', blend_t);
};
function cicloBlend(alfa0)
{
	blend_tmr = null;

	if(blend_elm) {
		setOpacity(blend_elm, alfa0);
		var tmp = 0.333 * (blend_alfa1 - alfa0);
		if(Math.abs(tmp) <= 0.01) {
			setOpacity(blend_elm, blend_alfa1);
			blend_elm = null;
		} else {
			alfa0 += tmp;
			blend_tmr = setTimeout('cicloBlend(' + alfa0 + ')', blend_t);
		}
	}
};

/*	Common */
function Muestra(id)
{
	setStyleById(id, 'visibility', 'inherit');
};
function Oculta(id)
{
	setStyleById(id, 'visibility', 'hidden');
};