// JavaScript Document
$(document).ready(function(){
	$(".main_principal img").each(function(index,element){
		if ($(this).attr("class") == 'menu_selected'){
			this.src = this.src.replace(".jpg","_hover.jpg");					   
		} else {
			$(this).hover(
				function(){
					this.src = this.src.replace(".jpg","_hover.jpg");					   
				}, function(){
					this.src = this.src.replace("_hover.jpg",".jpg");					   
				});		
		}
	});					   
});