Help with putting Frame inside Frame

Question

I have created two Frames: one with the code that works with the buttons (StudentsFile) and the second as a Tabbed Frame (TabbedPaneDemo).
I want to put StudentsFile into one of the tabs. The files compile but when I run TabbedPaneDemo the window that is created in StudentsFile comes up but it is not in the Tabbed window. What Am I doing wrong?
Any assistance would be appreciated.
This is the portion of the TabbedPaneDemo where I put in the StudentsFile into Panel 1.
public class TabbedPaneDemo extends JPanel {
    public TabbedPaneDemo() {
        super(new GridLayout(1, 1));
        JTabbedPane tabbedPane = new JTabbedPane();
        ImageIcon icon = createImageIcon("middle.gif");
        JComponent panel1 = makeTextPanel("Panel #1");      
       StudentsFile simpleTable = new StudentsFile();
        tabbedPane.addTab("Report", simpleTable);
        tabbedPane.setMnemonicAt(0, KeyEvent.VK_1);
        JComponent panel2 = makeTextPanel("Panel #2");
        tabbedPane.addTab("Tab 2", icon, panel2,
                "Does twice as much nothing");
        tabbedPane.setMnemonicAt(1, KeyEvent.VK_2);
        JComponent panel3 = makeTextPanel("Panel #3");
        tabbedPane.addTab("Tab 3", icon, panel3,
                "Still does nothing");
        tabbedPane.setMnemonicAt(2, KeyEvent.VK_3);
        JComponent panel4 = makeTextPanel(
                "Panel #4 (has a preferred size of 410 x 50).");
        panel4.setPreferredSize(new Dimension(410, 50));
        tabbedPane.addTab("Tab 4", icon, panel4,
                "Does nothing at all");
        tabbedPane.setMnemonicAt(3, KeyEvent.VK_4);
        //Add the tabbed pane to this panel.
        add(tabbedPane);
        //The following line enables to use scrolling tabs.
        tabbedPane.setTabLayoutPolicy(JTabbedPane.SCROLL_TAB_LAYOUT);
    }This is the portion of the StudentsFile where I setup the Frame.
public class StudentsFile extends JFrame
     //Sets Size of Frame
     private static final int WIDTH = 450;
     private static final int HEIGHT = 450;
     //Declares Text Fields
     private JTextField FNameTF, SIDTF, AddressTF, CityTF, StateTF, TelephoneTF ;
     //Declares Labels
     private JLabel FNameL, SIDL, AddressL, CityL, StateL, sheadingL,  TelephoneL, StatusL;
     //Declares Buttons
     private JButton openB, saveB, shelpB,sexitB, senterB ;
     private ButtonHandler bhHandler;
     //Declares Combobox that will list selections for teacher to select
     private JComboBox Selections;
     //Declares text areas     
     private JTextArea /*SoutputTA,*/ statusTA;
     //Declares filechooser for input/output file
     JFileChooser sfc = new JFileChooser();;
     //Creates object of StudentInformation
     private StudentInformation Studentdata = new StudentInformation();
public StudentsFile()
     //sets title and size of frame
     setTitle("Student Entries");
     setSize(WIDTH,HEIGHT);
     setBackground(Color.red);
     //Gets the frame
     Container pane = getContentPane();
     pane.setLayout(null);
     pane.setBackground(Color.yellow);
     //Creates button handler
     bhHandler = new ButtonHandler();
     //creates label to be used on pane
     sheadingL = new JLabel ("Student Information Center",
                    SwingConstants.CENTER);
     //sets the labels
     FNameL     = new JLabel("Student Name");
     SIDL       = new JLabel("Student ID");
     AddressL   = new JLabel("Address");
     CityL      = new JLabel("City");
     StateL         = new JLabel ("State");
     TelephoneL = new JLabel ("Telephone");
     StatusL        = new JLabel ("Status");
     //sets size of text fields
     FNameTF     = new JTextField(30);
     SIDTF       = new JTextField(20);
     AddressTF   = new JTextField(30);
     CityTF      = new JTextField(8);
     StateTF     = new JTextField(30);
     TelephoneTF = new JTextField(20);
     //sets size of text area to display status to teacher
     statusTA = new JTextArea(3, 10);
     //sets title of buttons and creates action listener
     openB = new JButton("Open");
     openB.addActionListener(bhHandler);
     saveB = new JButton("Save");
     saveB.addActionListener(bhHandler);
     senterB = new JButton ("Enter");
     senterB.addActionListener(bhHandler);
     shelpB = new JButton ("Help");
     shelpB.addActionListener(bhHandler);
     sexitB = new JButton ("Exit");
     sexitB. addActionListener(bhHandler);
     //Options that will appear in combo box
     String selection[] = {"Choose From The Available Options ",
                    "Add Student","Search for Student", 
                    "Edit Student Record","Delete Student Record"};
     Selections = new JComboBox(selection);
     //sets size of labels, text fields, buttons
     sheadingL.setSize(200,30);
     StatusL.setSize(50,20);
     SIDL.setSize(100,30);          
     SIDTF.setSize(200,30);       
     FNameL.setSize(100,30);          
     FNameTF.setSize(200,30);     
     CityL.setSize(100,30);          
     CityTF.setSize(200,30);          
     AddressL.setSize(100,30);     
     AddressTF.setSize(200,30);     
     StateL.setSize(100,30);          
     StateTF.setSize(200,30);     
     TelephoneL.setSize(100,30);     
     TelephoneTF.setSize(200,30);          
     statusTA.setSize(370, 30);
     Selections.setSize(400,30);
     openB.setSize(80,30);
     saveB.setSize(80,30);          
     shelpB.setSize(80,30);
     sexitB.setSize(80,30);
     senterB.setSize(80,30);
     //sets location of labels, text fields, buttons on frame
     sheadingL.setLocation(110,20);
     FNameL.setLocation(70,110);
     FNameTF.setLocation(170,110);
     SIDL.setLocation(70,140);
     SIDTF.setLocation(170,140);
     AddressL.setLocation(70,170);
     AddressTF.setLocation(170,170);
     CityL.setLocation(70,200);
     CityTF.setLocation(170,200);
     StateL.setLocation(70,230);     
     StateTF.setLocation(170,230);
     TelephoneL.setLocation(70,260);
     TelephoneTF.setLocation(170,260);
        StatusL.setLocation(30, 300);
     statusTA.setLocation(30, 330); 
     Selections.setLocation(20,60);
     openB.setLocation(20,370);     
     saveB.setLocation(100,370);
     senterB.setLocation(180,370);          
     shelpB.setLocation(260,370);
     sexitB.setLocation(340,370);
     //adds labels, text fields, buttons to pane
     pane.add(sheadingL);
     pane.add(SIDL);
     pane.add(SIDTF);
     pane.add(FNameL);
     pane.add(FNameTF);
     pane.add(AddressL);
     pane.add(AddressTF);
     pane.add(CityL);
     pane.add(CityTF);     
     pane.add(StateL);
     pane.add(StateTF);
     pane.add(TelephoneL);
     pane.add(TelephoneTF);
     pane.add (Selections);
     pane.add (openB);
     pane.add (saveB);
     pane.add (shelpB);
     pane.add (sexitB);
     pane.add(StatusL);
     pane.add(statusTA);
     pane.add(senterB);
     setVisible(true);
     setDefaultCloseOperation(EXIT_ON_CLOSE);
}

Answer 1

I haven't looked at all of your code, but I do see that you are trying to put a JFrame, which is a root container into a JTabbedPane, and this just cannot be done. It would be better to refactor your StudentsFile class to extend a JPanel, and then you can add it to a JTabbedPane.
Oh, and please ask these types of questions in the Swing forum.