JFrameからブラウザとJDialogを開いた際のウィンドウのアクティブ化について

import java.awt.Rectangle;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class JFrameTest extends JFrame {

  private static final long serialVersionUID = 1L;

  private JPanel jContentPane = null;

  private JButton jButton = null;

  /**
   * This is the default constructor
   */
  public JFrameTest() {
    super();
    initialize();
  }

  /**
   * This method initializes this
   * 
   * @return void
   */
  private void initialize() {
    this.setSize(300, 200);
    this.setContentPane(getJContentPane());
    this.setTitle("JFrame");
  }

  /**
   * This method initializes jContentPane
   * 
   * @return javax.swing.JPanel
   */
  private JPanel getJContentPane() {
    if (jContentPane == null) {
      jContentPane = new JPanel();
      jContentPane.setLayout(null);
      jContentPane.add(getJButton(), null);
    }
    return jContentPane;
  }

  /**
   * This method initializes jButton
   * 
   * @return javax.swing.JButton
   */
  private JButton getJButton() {
    if (jButton == null) {
      jButton = new JButton();
      jButton.setBounds(new Rectangle(14, 34, 264, 26));
      jButton.setText("ブラウザ起動＆ダイアログオープン");
      jButton.addActionListener(new java.awt.event.ActionListener() {
        public void actionPerformed(java.awt.event.ActionEvent e) {
          try {
            //IE起動
            Runtime.getRuntime().exec("\\"C:/Program Files/Internet Explorer/IEXPLORE.EXE\\" about:blank");
            Thread.sleep(3000); //ダイアログの起動をブラウザ起動より遅らせる
          } catch (Exception e1) {
            e1.printStackTrace();
          }
          //ダイアログオープン
          JDialog frame = new JDialog(JFrameTest.this, true);
          frame.setSize(100, 100);
          frame.setVisible(true);
        }
      });
    }
    return jButton;
  }

  public static void main(String[] args) {
    JFrameTest frame = new JFrameTest();
    frame.setSize(300, 300);
    frame.setVisible(true);
  }
}