displaying user friendly msg, when record is not found

Hi experts,
just a slight problem here.

I have a fully functional datagrid, that searches for data and fills the datagrid with the answer.
However, when there isn't any data i just what to display a  "msg not found" how do i actuall accomplish this.

thanks guys.

see code

      private void btnGo_Click(object sender, System.EventArgs e)
            {
                  //Connection string to the database
                  string connectionString = "server=TTTD.WORLD;User ID=ttt_currency_conversion;Password=ttt_currency_conversion";
                  OracleConnection con = new  OracleConnection(connectionString);
                  //select statement
                  string ora =
                        " SELECT GBP_EXCHANGE_PID, ISO_CODE, DATE_STAMP,  EXCHANGE_RATE " +
                        "  FROM GBP_CURRENCY_RATES  " +
                "  WHERE ISO_CODE LIKE'%"  + this.txtFind.Text.ToUpper() +"%' ";            //used upper for small letter entry
                  
                          //use an adapter in a disconnected enviroment
                  OracleDataAdapter adapter = new OracleDataAdapter(ora, connectionString);
                      //initialise the dataset for the adapter to use
                  DataSet ds = new DataSet();
                  //fill the dataset
                  adapter.Fill(ds);
                  //stop the paging index from miscalculating its position
                  //gets data and binds it to the grid
                  DgExchange.CurrentPageIndex=0;       
                  DgExchange.DataSource=ds;
                  DgExchange.DataBind();
                //close connection
                 con.Close();
                  
                        }

i tried using my old vb.net code but c# does not have the with keyword
   If dv.Count > 0 Then
            With DgRoles
                'stops
                .CurrentPageIndex = 0
                .DataSource = dv
                .DataMember = "Roles"
                .DataKeyField = "Roleid"
                DgRoles.DataBind()
            End With
 Else
                  'If no results, show message in label
            lblError.Text = "No Records Found. Please search again"
        End If