function getKeyCode(e) 
{
    if (window.event) { return window.event.keyCode; }
    return e.which;
}

function acceptDigitsOnly(e) {
    var key = getKeyCode(e);
    if (key >= 0x30 && key <= 0x39) { return true; }
    switch (key) {
        case 0x08:
        case 0x00:
            return true;
    }
    return false;
}