protected bool IsValidFormProvider()
    {
        string provider_id = Request.QueryString["staff"];

        return(provider_id != null && Regex.IsMatch(provider_id, @"^\d+$") && StaffDB.Exists(Convert.ToInt32(provider_id)));
    }
    private bool IsValidFormID()
    {
        string id = Request.QueryString["id"];

        return(id != null && Regex.IsMatch(id, @"^\d+$") && StaffDB.Exists(Convert.ToInt32(id)));
    }