Always first row data getting updated in ASP.Net GridView update

cmd.CommandText = "UPDATE tbl set SET c_amt=@c_amt,c_type=@c_type,status=@check WHERE id=@id"; 
cmd.Parameters.Add("@id", SqlDbType.Int).Value = Convert.ToInt32(GRD.DataKeys[e.RowIndex].Value.ToString());               
          
            
                cmd.Parameters.Add("@c_amt", SqlDbType.VarChar).Value = GRD.Rows[0].Cells[2].Text;
                cmd.Parameters.Add("@c_type", SqlDbType.VarChar).Value =GRD.Rows[0].Cells[3].Text;
                bool isChecked = ((CheckBox)GRD.Rows[0].Cells[4].Controls[0]).Checked;               
                cmd.Parameters.Add("@check", SqlDbType.Bit).Value = isChecked;

cmd.Connection = conn;
                conn.Open();
                cmd.ExecuteNonQuery();
                conn.Close();

i have above code whcih gives me proper id on debug but whe i update the selected row gets updated with the first row value