title: how to show custom message confirm on page load?
body: <p>I'm working on a page where I need to show a confirmation with custom text. This is my code and it works fine, but it doesn't show my message. The browser shows a default message, but I don't know why.</p>
  
  <pre><code>function unloadPage(){ 
      confirm(" i can't see this message");
      // same result when i try with : return "i can't see this message";
  }
  window.onbeforeunload = unloadPage;
  </code></pre>
  
  <p>Can anyone explain how to force the browser to take my custom confirm message, and ignore the default browser message?</p>