using (SqlConnection myconn = new SqlConnection(connstring))
{
using (SqlCommand mycomm = new SqlCommand("select * from employee", myconn))
{
mycomm.CommandType = CommandType.StoredProcedure;
myconn.Open(); /////Here u opened the connection but no close
SqlDataReader myread;
myread = mycomm.ExecuteReader();
dt.Load(myread);
}
}