EXTRAS = {
	// Event listener by Scott Andrew (www.scottandrew.com):
	addEvent : function(obj, evType, fn, useCapture){
		if (obj.addEventListener){
			try {
				obj.addEventListener(evType, fn, useCapture);
			} catch (e) {}
			return true;
			
			return true;
		} 
		else if (obj.attachEvent){
			var r = obj.attachEvent("on"+evType, fn);
			return r;
		} 
		else {
			return false;
		}
	}, 
	
	// Method adapted from Dan Pupius (pupius.co.uk):
	getElementsByClass : function(className,node) {
		if(!node) node=document;
		var refTags = document.all ? node.all : node.getElementsByTagName("*");
		var retVal = new Array();
		for(var z=0;z<refTags.length;z++) {
			if(refTags[z].className == className) 
			retVal.push(refTags[z]);
		}
		return retVal; 
	}
}

PNG = {
	load : function() {
		for (i=0;(im=document.images[i]);i++) {
			if (im.attachEvent) {
				if (/\.png$/i.test(im.src)) {
					im.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+im.src+"', sizingMethod='scale')";
					im.style.width = im.width+"px";
					im.style.height = im.height+"px";
					im.src = "img/blank.gif";
				}
			}
			else return;
		}
	}
}

HOV = {
	load : function() {
		for (i=0;(img=document.images[i]);i++) {
			if (/sobre/i.test(img.className)) {
				EXTRAS.addEvent(img,'mouseover',HOV.encima,true);
				EXTRAS.addEvent(img,'mouseout',HOV.fuera,true);
			}		
		}
	},
	encima : function(e) {
		var e = (e) ? e : window.event ;
		var target = (e.target) ? e.target : e.srcElement;
		//hay que añadirle "_hov" al nombre de img

		if ((target.attachEvent)&&(target.src.match(/blank.gif/))&&(target.style.filter)) {
			var r1 = target.style.filter.match(/\/img\/(.*)\.([jpg|png|gif|jpeg]*)/i);
			if (!r1) return;
			target.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='/img/"+r1[1]+"_hov."+r1[2]+"', sizingMethod='scale')";
	
		} else {
			var r1 = target.src.match(/\/img\/(.*)\.([jpg|png|gif|jpeg]*)/i);
			if (!r1) return;
			
			var imAux = new Image();
			imAux.src = "img/"+r1[1]+"_hov."+r1[2];
			imAux.onload = function () {
				target.src="img/"+r1[1]+"_hov."+r1[2];
			}
		}
		return true;		
	},
	fuera : function(e) {
		var e = (e) ? e : window.event ;
		var target = (e.target) ? e.target : e.srcElement;

		if ((target.attachEvent)&&(target.src.match(/blank.gif/))&&(target.style.filter)) {
			var r1 = target.style.filter.match(/img\/(.*)_hov\.([jpg|png|gif|jpeg]*)/i);
			if (!r1) return;//target.style.filter);// return;
			target.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='/img/"+r1[1]+"."+r1[2]+"', sizingMethod='scale')";
		} else {
			var r1 = target.src.match(/\/img\/(.*)_hov\.([jpg|png|gif|jpeg]*)/i);
			if (!r1) return;
			var imAux = new Image();
			imAux.src ="img/"+r1[1]+"."+r1[2];
			imAux.onload = function () {
				target.src="img/"+r1[1]+"."+r1[2];
			}


		}

		return false;		
	}
}

if(document.getElementsByTagName) {
	EXTRAS.addEvent(window,'load',PNG.load,false);
	EXTRAS.addEvent(window,'load',HOV.load,false);	
}