function changePriceBy()
{
	var price = document.getElementById("price_by"); //Element to change innerHTML
	var priceByKilo = document.getElementById("edit-attributes-3") //If this element exist, price by kilo, else: price by unit
	if(priceByKilo) {
		price.innerHTML += "/kilo";
	} else {
		price.innerHTML += "/unidad";
	}
}