function defaultDate(a, b)
{
    var aValue = trimAll(a.value);

    if (aValue == "")
    {
        return;
    }

    var d = parseDate(aValue);
    if (d == null)
    {
        return;
    }

    var bValue = trimAll(b.value);

    if (bValue == "" || compareDates(aValue, "MM/dd/yyyy", bValue, "MM/dd/yyyy") == 1)
    {
        b.value = aValue;
    }
}