How to block/detect Adblock by jQuery

<div class="myTestAd" style=" text-align:center;margin:10px">
 <!-- advert code goes here -->
</div>

function TestPage() {
    if ($('.myTestAd').height() == 0)
        alert("You are blocking my beautiful adverts, you swine!");
}

$(TestPage);

http://thepcspy.com/read/how_to_block_adblock/