Smooth transition needed for fade effect

I've added a fade effect to the following tabs here, but the transition isn't smooth, especially on the last 2 tabs.

I'd like it be like this page here.

Here's the Javascipt if someone could help:

$(window).load(function(){

    $('.tab:not(.aboutus)').fadeOut();

    $('.tabs li').click(function(){
        var thisAd = $(this).parent().parent();
        $(thisAd).children('.tab').fadeOut();
        $(thisAd).children('.'+$(this).attr('class').replace('tab','')).fadeIn();
        $('.tabs li').removeClass('active');                                                   
        $(this).addClass('active');
    });

                newContent.hide();
                currentContent.fadeOut(10, function() {
                    newContent.fadeIn(100);
                    currentContent.removeClass('current-content');
                    newContent.addClass('current-content');
                });

    if(window.location.hash) {
        if (window.location.hash == "#map") {
            $(".Advert").children('.tab').fadeOut();
            $(".Advert").children('.map').fadeIn();
            $('.tabs li').removeClass('active');                                                   
            $('.maptab').addClass('active');
        }
        if (window.location.hash == "#voucher") {
            $(".Advert").children('.tab').fadeOut();
            $(".Advert").children('.vouchers').fadeIn();
        }
    }   

});

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