Bring you to the definition.

dt.js

/* 
    when you click on <a class="dt">Hello</a> and a
    <dt>Hello</dt> is on the same page, the page scrolls
    to that location.
*/
$(document).ready(function () {
    $('a.dt', document).each(function () {
        var that = $(this), rel = that.attr('href') ||
            that.text().replace(/\s+/g, ' ');
        if (!rel) {
            return;
        }
        var correspondingDT = $('dt', document).filter(function (idx) {
            return ($(this).text().toLowerCase() === rel.toLowerCase());
        });

        if (!(correspondingDT && correspondingDT.length)) {
            return;
        }
        that.click(function (event) {
            event.preventDefault();
            $('html, body').animate({
                'scrollTop': correspondingDT.offset().top
            }, 650);

            // highlight
            var oldBg = correspondingDT.css('background-color') || 'transparent';
            correspondingDT.css({'background-color': '#ff0'})
                           // requires $.Color
                           .animate({'background-color': oldBg}, 2500)
                           .css({'background-color': oldBg});
        }).prop('title',
            rel + '\n\n' + correspondingDT.next('dd').text().replace(/\s+/g,
                ' ')).css('cursor', 'help');

        // reverse highlight
        var thatBg = that.css('background-color') || 'transparent';
        correspondingDT.mouseenter(function () {
                that.css({'background-color': '#ff0'});
            }).mouseout(function () {
                that.animate({'background-color': thatBg}, 2500)
                    .css({'background-color': thatBg});
            });
    });
});