private void Radnik() {


    String sql = "SELECT * FROM korisnici INNER JOIN karte ON korisnici .ID = karte .ID WHERE korisnici.USERNAME =?";
        try{

        pst= (PreparedStatement) conn.prepareStatement(sql);
        rs=pst.executeQuery();

        if(rs.next()) {

        String add1=rs.getString("imeprez");
        ukupnoL.setText(add1);


        }


        }catch(Exception e){

            JOptionPane.showMessageDialog(null, e);
        }