| <!DOCTYPE html> | |
| <html> | |
| <body> | |
| <select id="s"> | |
| <option value="a">a</option> | |
| <option value="b">b</option> | |
| </select> | |
| <script> | |
| const s = document.getElementById('s'); | |
| s.addEventListener('change', () => { | |
| // Remove the mid iframe from the top window. | |
| // Since mid is cross-origin, removing it synchronously detaches this frame. | |
| parent.parent.document.getElementById('mid').remove(); | |
| }); | |
| </script> | |
| </body> | |
| </html> |