$.fn.imageHover = function(image_url_hover) {
    var obj = $(this);
    var image_url = obj.attr('src');
    obj.hover(function() {
        obj.attr('src', image_url_hover);
    }, function() {
        obj.attr('src', image_url);
    });
}

$.fn.smoothScroll = function() {
    var obj = this;

    obj.click(function() {
        $('html, body').animate({
            scrollTop: $('#' + obj.id).offset().top
        }, 2000);
        
        return false;
    });
}