function ff_real(element, message)
{
    var ex  = /(^-?\d\d*\.?\d*$)/;
    if (!ex.test(element.value)) {
        if (message=='') message = element.name+" must be a number.\n";
        ff_validationFocus(element.name);
        return message;
    } // if
    return '';
} // ff_real