beforeUnload.html (448B)
1 <!doctype html> 2 <meta name="viewport" content="width=device-width, initial-scale=1" /> 3 <p> 4 Focus on the text field, then focus on the url bar and navigate to another 5 site. 6 <br /> 7 <input id="nameInput" /> 8 <script> 9 nameInput.addEventListener("focus", event => { 10 addEventListener("beforeunload", e => { 11 document.body.innerHTML = "<h1>beforeunload fired</h1>"; 12 e.preventDefault(); 13 }); 14 }); 15 </script> 16 </p>