$(document).ready(function(){
    var totalElements = $(".menuCategoriaPrin li");
    var totalAncho = 0
    $.each(totalElements, function(){
        totalAncho += $(this).width() + 3;
    });
    
    $(".menuCategoriaPrin").css("width",totalAncho);
    $(".drop_down").css('opacity',0.9);
    menuDinamico();
});
function menuDinamico(){
    $("li.categoriaShow").hover(
        function(){           
            $(this).find(".drop_down:first").fadeIn("slow");
        },function(){            
            $(this).find(".drop_down:first").hide();
        }
     );
}