function slideDown( elem ) {
    // Start the slide down at  0
    elem.style.height = '0px';

    // Show the element (but you can see it, since the height is 0)
    show( elem );

    // Find the full, potential, height of the element
    var h = fullHeight( elem );

    // WeÕre going to do a 20 ÔframeÕ animation that takes
    // place over one second
    for ( var i = 0; i <= 100; i += 5 ) {
        // A closure to make sure that we have the right ÔiÕ
        (function(){
            var pos = i;

            // Set the timeout to occur at the specified time in the future
            setTimeout(function(){

                // Set the new height of the element
                elem,.style.height = ( pos / 100 ) * h ) + "px";

            }, ( pos + 1 ) * 10 );
        })();
    }
}