We have modified your code. Here it is:

JFrame main=new JFrame("Home-THE SECURED PARKING SERVICE MAIN PAGE");
    main.getContentPane().setBackground(Color.blue);

    JPanel titlePanel=new JPanel();
    JLabel heading=new JLabel("*******THE SECURED PARKING SERVICES*******",JLabel.CENTER);
    heading.setOpaque(true);
    heading.setBackground(Color.orange);
    heading.setForeground(Color.black);
    heading.setFont(new Font("Serif", Font.BOLD, 35));
    titlePanel.setBackground(Color.blue);
    titlePanel.add(heading);
    //entrypanel and textfields

    JPanel entryPanel=new JPanel();
    entryPanel.setLayout(new BoxLayout(entryPanel,BoxLayout.Y_AXIS));
    JTextField name=new JTextField(10);
    name.setBounds(0, 0, 20, 50);   
    JTextField custid=new JTextField(10);
    JTextField address=new JTextField(10);
    JTextField dob=new JTextField(10);
    JTextField vehiclename=new JTextField(10);
    JTextField vehiclereg_no=new JTextField(10);
    JTextField license_no=new JTextField(10);
    entryPanel.add(name);
    entryPanel.add(custid);
    entryPanel.add(address);
    entryPanel.add(dob);
    entryPanel.add(vehiclename);
    entryPanel.add(vehiclereg_no);
    entryPanel.add(license_no);
    main.add(titlePanel);
    main.add(entryPanel);
    main.setLayout(new BoxLayout(main.getContentPane(),BoxLayout.Y_AXIS));
    main.setSize(1368,770);//exact window size
    main.setVisible(true);
    main.setDefaultCloseOperation(main.EXIT_ON_CLOSE);

Huh!! Nothing different. Please post me the correct one by indicating the incorrect ones..