public class MainFrame extends javax.swing.JFrame {
...
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                
                MainFrame frame = new MainFrame();
                
                frame.setVisible(true);
                
                CheckStatus checkstatus = new CheckStatus(frame);
     
                
            }
        });
    }

....
}