datatable.select() problem

Hi friend, i want to get a particular row or values from datatable which is containing values of a xml file using datatable.select().  I had done like this but the search is not working .
 The below code is inside
button_click event()
{

DataTable dt = new DataTable("Dynamically_Generated");
 dt.Columns.Add("Id", typeof(int));
        dt.Columns.Add("Name", typeof(string));
        dt.Columns.Add("Address", typeof(string));
        dt.Columns["Id"].AutoIncrement = true;

     dt.ReadXml(@"c:\\a.xml");

        DataRow dr1 = dt.NewRow();
        dr1["Name"] = txtnm.Text;
        dr1["Addres ...