You need to add a WindowListener to your Frame.

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If you want to track the JButton clicks, use a Map<JButton, Integer> to map the JButtons to their counts. And the Frame setTitle() method can be used to update the title.

I want to comment as well on your code. First, it isn't good practice to mix AWT and Swing. Stick with Swing, as AWT is a dead technology. Second, use arrays and loops. If you have variables named b1, b2, b3, b4, etc., that is begging for an array. Lastly, your code is not easy to read. Please properly format your code for others to read.