hey i have some problems with this code... This is a JDialogForm in which I have jTextField and button. I want to save data from this Jtextfield when i click button to use it in another window but i don't know why it doesn't work. I always get Exception ek and the message i have put there.

 private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    String sciezka = jTextField1.getText();
    if (sciezka.length() > 0)
    {
      Zmienne_pomocnicze zp = new Zmienne_pomocnicze();
      zp.setPrzechowaj(sciezka);
       try {
       ObjectOutputStream oos = new ObjectOutputStream (new FileOutputStream("danebaza"));
       oos.writeObject(zp);

       oos.close();


   } catch(Exception ek) {
       JOptionPane.showMessageDialog(null, "Nie mozna pobrac nazwy_przedmiotu: " + ek);
     }
   }
    this.setVisible(false);
}                    

where class Zmienne_pomocnicze looks like this

public class Zmienne_pomocnicze {

    public String n;


    public void setPrzechowaj (String neew){
        n = neew;

    } public String getPrzechowaj () {
        return n; 
    } 
}

i guess the problem is with oos.writeObject(zp); but i don't know why.