Alguien ha sugerido usar una declaración preparada, pero no sé cómo usarla. ¿Qué cambios tengo que hacer en mi código?

try
{
    Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
    System.out.println("\n Driver loaded");

    Connection con = DriverManager.getConnection("jdbc:odbc:wanisamajDB");

    Statement stmt = con.createStatement();
    System.out.println("statement is created");

    // System.out.println(Integer.parseInt(cbregn.getSelectedItem().toString()));

    String qry = " UPDATE Registration1 SET RegistrationNo = '"+cbregn.getSelectedItem()+"',SeniorPerson = '"+cbnm.getSelectedItem()+"', NativePlace = '"+tfplace.getText()+"',Kul = '"+tfkul.getText()+"', Gotra = '"+tfgotra.getText()+"' ,KulSwami = '"+tfswami.getText()+"', ResidensialAddress = '"+taraddr.getText()+"' , PinCode = '"+tfpcd.getText()+"', STDcode = '"+tfstdcode.getText()+"',TelephoneNo = '"+tftele.getText()+"', MobileNo = '"+tfmno.getText()+"', Email = '"+tfemail.getText()+"',Website ='"+tfweb.getText()+"',Education ='"+tfedu.getText()+"',Branch ='"+tfbrch.getText()+"',BloodGroup ='"+cbbldgrp.getSelectedItem()+"' where SeniorPerson='" +cbnm.getSelectedItem().toString()+"'" ;

          stmt.executeUpdate(qry);

          JOptionPane.showMessageDialog(null,"RECORD IS UPDATED SUCCESSFULLY ");
          System.out.println("QUERY");       

          // cbregn.setEditable(false);
          cbnm.setEditable(false);
          tfplace.setEditable(false);
          tfkul.setEditable(false);
          tfgotra.setEditable(false);
          tfswami.setEditable(false);
          taraddr.setEditable(false);
          tfpcd.setEditable(false);
          tfstdcode.setEditable(false);
          tftele.setEditable(false);
          tfmno.setEditable(false);
          tfemail.setEditable(false);
          tfweb.setEditable(false);
          tfedu.setEditable(false);
          tfbrch.setEditable(false);
          cbbldgrp.setEditable(false);
          con.close();
          stmt.close();
        }
//            catch(SQLException eM)
//            {
//            JOptionPane.showMessageDialog(null,"RECORD IS NOT FOUND ");
//            }
        catch(Exception et)
        {
             et.printStackTrace();
          //  System.out.println("error:"+et.getMessage());
        }