function Navigate(event) {
    //debugger;
    
    if (window.event) // IE
    {
        keyCode = event.keyCode
    }
    else if (event.which) // Netscape/Firefox/Opera
    {
        keyCode = event.which
    }

    /*var keyCode = event.which;
    if (keyCode == undefined) {
        keyCode = event.keyCode;*/

    switch (keyCode) {
        case 37: //left arrow
            goPrevious();
            break;
        case 38: //up arrow
            goPrevious();
            break;
        case 39: //right arrow
            goNext();
            break;
        case 40: //down arrow
            goNext();
            break;
        case 27: //esc
            window.close();
            break;
        }
    //alert("The Unicode key code is: " + keyCode);
}

function goPrevious() {
    var loPrevious = document.getElementById("lnkPrevious");
    if ((loPrevious != "undefined") && (loPrevious != null))
        window.location = loPrevious.href;
}
function goNext() {
    var loNext = document.getElementById("lnkNext");
    if ((loNext != "undefined") && (loNext != null))
        window.location = loNext.href;
}