var current = 0;
var toc = document.getElementById("toc");
var links = toc.getElementsByTagName("tr");
var num = links.length;

for (var i = 0; i < num; i++)
    links[i].id = "l" + (i + 1); 

document.onkeydown = handleKey;

function handleKey(e)
{
    if (!e)
        var e = window.event;

    (e.keyCode) ? key = e.keyCode : key = e.which;

    try
    {
        switch (key)
        {
            case 13: // enter
                if ((current > 0) && (current <= num))
                {
                    var dest = document.getElementById("l" + current).getElementsByTagName('a');
                    if (dest.length > 0)
                        document.location = dest[0].href;
                }
                break;
            case 38: // up
                if (current > 1)
                {
                    document.getElementById("l" + current).className = null;
                    current--;
                    document.getElementById("l" + current).className = "selected";
                }
                break;
            case 40: // down
                if (current == 0)
                {
                    current = 1;
                    document.getElementById("l1").className = "selected";
                }
                else if (current < num)
                {
                    document.getElementById("l" + current).className = null;
                    current++;
                    document.getElementById("l" + current).className = "selected";
                }
                break;
        }
    }
    catch(Exception) {};
}