JOptionPane Won't Display When ResultSet = null

Question

I wrote the following method to connect to an Access database via JDBC. Everything works properly except for the dialog box. It doesn't show up when the SQL query doesn't return anything. I've tried using the JOptionPane as an if, an else if, and an else without any luck. I know the syntax of the JOptionPane statement is correct, as it works in other parts of the program. Can anyone help? Thanks, Scott
P.S. I know I should use a do while loop to populate the text fields...this is just a quick and dirty beta program.
     public void database(String query)
          try
          Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
          String dataSourceName = "testdatabase";
          String dbURL = "jdbc:odbc:" + dataSourceName;
          Connection con = DriverManager.getConnection(dbURL,"","");
          Statement s = con.createStatement();
          s.execute(query);
          ResultSet rs = s.getResultSet();
               if (rs != null)
               while ( rs.next() )
               field2.setText(rs.getString(2));
                    field3.setText(rs.getString(3));
                    field4.setText(rs.getString(4));
                    field5.setText(rs.getString(5));
                    field6.setText(rs.getString(6));
                    field7.setText(rs.getString(7));
                    field8.setText(rs.getString(8));
                    field9.setText(rs.getString(9));
                    field10.setText(rs.getString(10));
                    field11.setText(rs.getString(11));
                    field12.setText(rs.getString(12));
               if (rs == null)     JOptionPane.showMessageDialog(null, "UPC not found!");
               s.close();
          con.close();
     catch (Exception err)
          System.out.println("ERROR: " + err);
     }

Answer 1

I changed the line to:
if(! rs.next()) JOptionPane.showMessageDialog(null,
"UPC not found!");
...and now the dialog box pops up every time, even if
there is data. Did I do something wrong with the
syntax?Well no.. except that by the time you check you have already iterated through the result set and next returns false.
I was thinking about something like this (and please in future use the code tags for pretty formatting like below... it makes it easier to read and the forum software will "eat" some of your code without it sometimes)
boolean hasResults = false; // new line
while ( rs.next() )
    hasResults = true; // there was at least one row
    field2.setText(rs.getString(2));
    field3.setText(rs.getString(3));
    field4.setText(rs.getString(4));
    field5.setText(rs.getString(5));
    field6.setText(rs.getString(6));
    field7.setText(rs.getString(7));
    field8.setText(rs.getString(8));
    field9.setText(rs.getString(9));
    field10.setText(rs.getString(10));
    field11.setText(rs.getString(11));
    field12.setText(rs.getString(12));
if (!hasResults) JOptionPane.showMessageDialog(null, "UPC not found!");