Value using data merging

Question

DataTable dt = ex.data(name,age);

DataTable Stud = new DataTable();

if (dt.Rows.Count > 0)

{

for (int i = 0; i < dt.Rows.Count; i++)

{

name = dt.Rows[i]["name"].ToString();

address= dt.Rows[i]["addres"].ToString();

DataSet dtList = ex.Result(id);

dtStud.Merge(dtList.Tables[4]);

dtStud.AcceptChanges();

}

}

Stud = Stud.DefaultView.ToTable(true, "name", "age", "add1", "add2", "phn",);

 

 

first user login time this code will working. den another user login after processing this code will'nt working. what should i do?

thnkx in adv.