title: how could i make the JFrame content change to corresponding click?
body: <p>I am working on a simple desktop application with java. There is a menu bar, when the user clicks on menu item 1 then the content will change to form A. When a user clicks on menu item 2 then the content will display form B.</p>
  
  <p>How could i achieve this?</p>
  
  <p><strong>using the same window</strong> and just the content change.</p>