Hi,
I have got the expected out by applying following changes in my code:
1. Changed return type from String to Stream
2. Replaced the code
return (new JavaScriptSerializer().Serialize(dict));
with
WebOperationContext.Current.OutgoingResponse.ContentType = "application/json; charset=utf-8";
return new MemoryStream(Encoding.UTF8.GetBytes(sData));
Thanks everybody for help and support.
Thanks
Rajesh