title: Unchecked or unsafe operations error in java compile?
body: <p>I am completing a lab assignment for school and get this error when I compile. The program runs fine, bit would like to fix what is causing the error. The program code and the complete error is below. Thanks as always!</p>
  
  <p>Error:
  Note: F:\Java\Lab 8\Lab8.java uses unchecked or unsafe operations.
  Note: Recompile with -Xlint:unchecked for details.</p>
  
  <p>Code:</p>
  
  <pre><code>   import java.awt.*;
     import java.awt.event.*;
     import javax.swing.*;
     import javax.swing.event.*;
     import javax.swing.border.*;
  
  
     public class Lab8 extends JFrame {
         public Lab8()
             {
  
             // Create an array of Strings for age ranges
             String[] ageRanges = {"Under 20", "20-29", "30-39", "40-49", "50-59", "60 and Above"};
             JComboBox jcbo = new JComboBox(ageRanges);
  
             // Create an array of String destinations
             String[] destination = {"Mercury", "Venus", "Moon", "Mars", "Jupiter / Europa", "Saturn / Triton", "Pluto + Sharon"};
             JList jlst = new JList();
  
             // Declare radio buttons
             JRadioButton jrbMonday, jrbTuesday, jrbWednesday, jrbThursday, jrbFriday;
  
             // Create a textfield
             JTextField jMsg = new JTextField(10);
  
  
             // Create panel to hold label and textbox.
             JPanel p1 = new JPanel();
             p1.setLayout(new BorderLayout(5,0));
             p1.add(new JLabel("Name: "), BorderLayout.WEST);
             p1.add(new JTextField(20), BorderLayout.CENTER);
             jMsg.setHorizontalAlignment(JTextField.LEFT);
  
  
             // Create combobox panel.
             JPanel p2 = new JPanel();
             p2.setLayout(new GridLayout(2,0,5,5));
             p2.add(p1, BorderLayout.NORTH);
             p2.add(new JComboBox(ageRanges), BorderLayout.CENTER);
                 p2.setBorder(new TitledBorder("Passenger Name &amp; Age Range"));
  
  
             //Create listbox panel.
             JPanel p3 = new JPanel();
             p3.setLayout(new GridLayout(1, 0));
             p3.add(new JList(destination));
                 p3.setBorder(new TitledBorder("Destinations"));
  
  
             // Create a new panel to hold radio buttons.
                 JPanel r1 = new JPanel();
             r1.setLayout(new GridLayout(3,2));
             r1.add(jrbMonday = new JRadioButton("Monday"));
             r1.add(jrbTuesday = new JRadioButton("Tuesday"));
             r1.add(jrbWednesday = new JRadioButton("Wednesday"));
             r1.add(jrbThursday = new JRadioButton("Thursday"));
             r1.add(jrbFriday = new JRadioButton("Friday"));
             r1.setBorder(new TitledBorder("Departure Days"));
  
  
             // Create a radio button group to group five buttons
             ButtonGroup group = new ButtonGroup();
             group.add(jrbMonday);
             group.add(jrbTuesday);
             group.add(jrbWednesday);
             group.add(jrbThursday);
             group.add(jrbFriday);
  
  
             // Create grid to hold contents
             JPanel pMain = new JPanel();
             pMain.setLayout(new BorderLayout(5,0));
             add(r1, BorderLayout.CENTER);
             add(p2, BorderLayout.NORTH);
             add(p3, BorderLayout. EAST);
  
  }
  
  
  public static void main(String[] args)
         {
             Lab8 frame = new Lab8();
             frame.pack();
             frame.setTitle("Lab 8 Application");
             frame.setLocationRelativeTo(null); // Center the frame
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setSize(425, 275);
             frame.setVisible(true);
          }
  }
  </code></pre>