function preload(img) {
	//Image preload
	var img1 = new Image;
	
	for(i=0; i<img.length; i++) {
		img1.src = img[i];
	}
}


function switch_imgs() {
	//Automatically add roll over image to images
	
	imgs = document.getElementsByTagName('img');
	newsrc = Array();
	newsrc_nid = Array();
	oldsrc = Array();
	
	for(i=0; i<imgs.length; i++) {
		status = imgs[i].src.substr((imgs[i].src.length-7), 3);
		
		if(status=='off') {

			oldsrc[imgs[i].id] = imgs[i].src;
			newsrc[imgs[i].id] = imgs[i].src.replace('_off.', '_on.');
			newsrc_nid[i] = imgs[i].src.replace('_off.', '_on.');
			
			
			imgs[i].onmouseover = function() {
				this.src = newsrc[this.id];	
			}
			
			imgs[i].onmouseout = function() {
				this.src = oldsrc[this.id];	
			}
		}
		
	}
	
	return newsrc_nid;
	
}

function muestra() {
	Element.setOpacity('muestraFHG', 0.8);
	$('muestraFHG').style.top = ((document.body.offsetHeight/2) - 84) + 'px';
	$('muestraFHG').style.left = ((document.body.offsetWidth/2) - 192) + 'px';
}

window.onload = function() {
	preload(switch_imgs())
}