private void start()throws Exception{
        Loginobject= new Login();
        Loginobject.btnlogin.addActionListener(link);
        Loginobject.btnclear.addActionListener(link);
        Loginobject.btnre.addActionListener(link);
        count = new File("count.txt");
        s = new Scanner(count);
        totalnumber = Integer.parseInt(s.nextLine());
        Userlist = new User[totalnumber];
        User s;
        if( totalnumber>0 ){
            File file = new File("User.txt");
	    Scanner inputFile = new Scanner(file);
	    String name = "";
	    String pw="";
            String email="";
            for(int i=0; i<totalnumber; i++){
                name = inputFile.nextLine();
                pw=inputFile.nextLine();
                email=inputFile.nextLine();
                Userlist[i] = new User(name,pw,email);
                System.out.println(Userlist[i].getName());
                inputFile.nextLine();
            }
        }
    }

   private class Navigate implements ActionListener{

       public void actionPerformed (ActionEvent e){
           //Login
           if (e.getSource()==Loginobject.btnlogin){
                   if(!validateLoEmpty()){
                  Loginobject.frame.setVisible(false);
                Menuobject=new Menu();
               }



           }

           else if (e.getSource()==Loginobject.btnclear){
            Loginobject.txtpw.setText("");
            Loginobject.txtuser.setText("");
           }
           else if (e.getSource()==Loginobject.btnre){
               Registerobject= new Register();
               Loginobject.frame.setVisible(false);
               Registerobject.btnclear.addActionListener(link);
               Registerobject.btnsave.addActionListener(link);
               Registerobject.btncancel.addActionListener(link);

           }
           //Register
           else if (e.getSource()==Registerobject.btnclear){
               Registerobject.txtemail.setText("");
               Registerobject.txtuser.setText("");
               Registerobject.txtpw.setText("");

           }
           else if (e.getSource()==Registerobject.btncancel){
               Registerobject.frame.setVisible(false);
               Loginobject.frame.setVisible(true);

           }

           else if (e.getSource()==Registerobject.btnsave){
               if(!validateReEmpty()){
                   if(!validateExist()){
                  saveFile();
               }
               }






           }
           //Menu

       }
       public boolean validateLoEmpty(){
            boolean empty=false;
            String username=Loginobject.txtuser.getText();
            String password=Loginobject.txtpw.getText();

            if(username.length()<1){
                        JOptionPane.showMessageDialog(Registerobject.frame, "Empty username");
                        empty=true;
                        }
            else if(password.length()<1){
                        JOptionPane.showMessageDialog(Registerobject.frame, "Empty password");
                        empty=true;
            }

            return empty;

}
       public boolean validateReEmpty(){
            boolean blank=false;
            String username=Registerobject.txtuser.getText();
            String password=Registerobject.txtpw.getText();
            String email=Registerobject.txtemail.getText();
            if(username.length()<1){
                        JOptionPane.showMessageDialog(Registerobject.frame, "Empty username");
                        blank=true;
                        }
            else if(password.length()<1){
                        JOptionPane.showMessageDialog(Registerobject.frame, "Empty password");
                        blank=true;
            }
            else if(email.length()<1){
                        JOptionPane.showMessageDialog(Registerobject.frame, "Empty email");
                        blank=true;
            }
            return blank;

}
       public boolean validateExist(){

           String username=Registerobject.txtuser.getText();
           boolean check=false;
                   try{
                       FileReader fr= new FileReader("User.txt");
                       BufferedReader br= new BufferedReader(fr);
                       String name=br.readLine();
                       while (name!=null){
                           name=br.readLine();
                           if(username.equals(name)){
                               check= true;
                               JOptionPane.showMessageDialog(Registerobject.frame, "Invalid username");
                               break;
                           }else check=false;
                       }
                       fr.close();
                       br.close();
                   }
                   catch(IOException e){

                       e.printStackTrace();
                   }
                   return check;
       }
       public void saveFile(){
       try{
                         if( totalnumber>0 ){
                    PrintWriter dataFile = new PrintWriter("User.txt");
                    for(int i=0; i<totalnumber; i++){
                        dataFile.println(Userlist[i].getName());
                        dataFile.println(Userlist[i].getPw());
                        dataFile.println(Userlist[i].getEmail());
                        dataFile.println();
                    }
                    dataFile.close();
                }
                outputFile = new PrintWriter("count.txt");
                outputFile.println(totalnumber);
                outputFile.close();

             }
                catch (IOException e){
                 System.out.println("Error!");
             }
        }




   }
}