I found error message :- The select command property has not been initialize before calling 'fill'. The code (.asmx.cs) is as below:-

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data;
using System.Data.SqlClient;

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
public class empwebservice : System.Web.Services.WebService {

public empwebservice () {
}

[WebMethod]
public DataSet getData()
{
SqlConnection conn = new SqlConnection(@"Data Source=.; Initial Catalog= master;Integrated Security= True;");
SqlCommand cmd = new SqlCommand(" select * from emp", conn);

SqlDataAdapter da = new SqlDataAdapter();
DataSet ds = new DataSet();
da.Fill(ds,"empnew");

return ds;
}


}
Error shows ( select command property has not been initialize) da.Fill(ds,"empnew").
What is the solution please tell me.