/// <summary>
        /// Generate the necessary parameters
        /// </summary>
        public List <KeyValuePair <string, string> > GetParams()
        {
            var p = new List <KeyValuePair <string, string> >();

            if (PhoneNumber != null)
            {
                p.Add(new KeyValuePair <string, string>("PhoneNumber", PhoneNumber.ToString()));
            }

            if (FriendlyName != null)
            {
                p.Add(new KeyValuePair <string, string>("FriendlyName", FriendlyName));
            }

            if (CallDelay != null)
            {
                p.Add(new KeyValuePair <string, string>("CallDelay", CallDelay.ToString()));
            }

            if (Extension != null)
            {
                p.Add(new KeyValuePair <string, string>("Extension", Extension));
            }

            if (StatusCallback != null)
            {
                p.Add(new KeyValuePair <string, string>("StatusCallback", Serializers.Url(StatusCallback)));
            }

            if (StatusCallbackMethod != null)
            {
                p.Add(new KeyValuePair <string, string>("StatusCallbackMethod", StatusCallbackMethod.ToString()));
            }

            return(p);
        }