<title>Solution for Long Dropdowns</title>

<script type='text/javascript' src='http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js?ver=1.3.2'></script>


<script>

    var maxHeight = 400;

$(function(){

$(".dropdown > li").hover(function() {

     var $container = $(this),
         $list = $container.find("ul"),
         $anchor = $container.find("a"),
         height = $list.height() * 1.1,       // make sure there is enough room at the bottom
         multiplier = height / maxHeight;     // needs to move faster if list is taller

    // need to save height here so it can revert on mouseout            
    $container.data("origHeight", $container.height());

    // so it can retain it's rollover color all the while the dropdown is open
    $anchor.addClass("hover");

    // make sure dropdown appears directly below parent list item    
    $list
        .show()
        .css({
            paddingTop: $container.data("origHeight")
        });

    // don't do any animation if list shorter than max
    if (multiplier > 1) {
        $container
            .css({
                height: maxHeight,
                overflow: "hidden"
            })
            .mousemove(function(e) {
                var offset = $container.offset();
                var relativeY = ((e.pageY - offset.top) * multiplier) - ($container.data("origHeight") * multiplier);
                if (relativeY > $container.data("origHeight")) {
                    $list.css("top", -relativeY + $container.data("origHeight"));
                };
            });
    }

}, function() {

    var $el = $(this);

    // put things back to normal
    $el
        .height($(this).data("origHeight"))
        .find("ul")
        .css({ top: 0 })
        .hide()
        .end()
        .find("a")
        .removeClass("hover");

});

// Add down arrow only to menu items with submenus
$(".dropdown > li:has('ul')").each(function() {
    $(this).find("a:first").append("<img src='images/down-arrow.png' />");
});

});

<div id="page-wrap">

    <h1>Long Dropdowns</h1>

    <p>If your dropdowns are this long, you might wanna take a re-look at your navigational strategy. But, if it makes sense, a 
    technique like this may be beneficial.</p>

    <p>PROBLEM: Dropdown menu goes down below the fold when opened, making lower items inaccesible.</p>

    <p>SOLUTION? Make menu scroll up and down as you mouse through it.</p>

    <ul class="dropdown">
        <li><a href="#">Really Tall Menu</a>
            <ul class="sub_menu">
                 <li><a href="#">Artificial Turf</a></li>
                 <li><a href="#">Benches &amp; Bleachers</a></li>
                 <li><a href="#">Communication Devices</a></li>
                 <li><a href="#">Dugouts</a></li>
                 <li><a href="#">Fencing &amp; Windscreen</a></li>
                 <li><a href="#">Floor Protectors</a></li>
                 <li><a href="#">Foul Poles</a></li>
                 <li><a href="#">Netting</a></li>
                 <li><a href="#">Outdoor Furniture &amp; Storage</a></li>
                 <li><a href="#">Outdoor Signs</a></li>
                 <li><a href="#">Padding</a></li>
                 <li><a href="#">Scoreboards</a></li>
                 <li><a href="#">Shade Structures</a></li>
                 <li><a href="#">Artificial Turf</a></li>
                 <li><a href="#">Benches &amp; Bleachers</a></li>
                 <li><a href="#">Communication Devices</a></li>
                 <li><a href="#">Dugouts</a></li>
                 <li><a href="#">Fencing &amp; Windscreen</a></li>
                 <li><a href="#">Floor Protectors</a></li>
                 <li><a href="#">Foul Poles</a></li>
                 <li><a href="#">Netting</a></li>

            </ul>
        </li>
        <li><a href="#">Kinda Tall Menu</a>
            <ul class="sub_menu">
                 <li><a href="#">Artificial Turf</a></li>
                 <li><a href="#">Benches &amp; Bleachers</a></li>
                 <li><a href="#">Communication Devices</a></li>
                 <li><a href="#">Dugouts</a></li>
                 <li><a href="#">Fencing &amp; Windscreen</a></li>
                 <li><a href="#">Floor Protectors</a></li>
                 <li><a href="#">Foul Poles</a></li>
                 <li><a href="#">Netting</a></li>
                 <li><a href="#">Outdoor Furniture &amp; Storage</a></li>
                 <li><a href="#">Outdoor Signs</a></li>
                 <li><a href="#">Padding</a></li>
                 <li><a href="#">Scoreboards</a></li>
            </ul>
        </li>
        <li><a href="#">Average Menu</a>
            <ul class="sub_menu">
                 <li><a href="#">Artificial Turf</a></li>
                 <li><a href="#">Benches &amp; Bleachers</a></li>
                 <li><a href="#">Communication Devices</a></li>
                 <li><a href="#">Dugouts</a></li>
                 <li><a href="#">Fencing &amp; Windscreen</a></li>
            </ul>
        </li>
            <li><a href="#">No Menu</a>
        </li>
    </ul>

</div>