json with jarray

hi,

 

i am using below code for serializing jsn array but i getting error every time i.e Input string was not in a correct format. i need below json format .

 

{"id": ["99999", "8888","888881","6666","7777"]} 

 

please help me .also let me know how to send this json request to user

code--

 

string Mnumber;
string data;
List s = new List();
// from data reader i m getting data from table
if (rdr.HasRows)
{
while (rdr.Read())
{

Mnumber = rdr[0].ToString();
if (Mnumber.Substring(0, 2) == "91" && Mnumber.Length == 12)
{
Mnumber = Mnumber.Remove(0, 2);
s.Add(Mnumber.ToString());
}


}
RootObject ar2 = new RootObject();


ar2.id = s;

data = JsonConvert.SerializeObject(ar2); //error line  -- Input string was not in a correct format.
} 

 

 

 

public class RootObject
{
public List id { get; set; }
}