| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <meta name="viewport" content="width=device-width, initial-scale=1"> | |
| </head> | |
| <script> | |
| function runTest() { | |
| checkbox.indeterminate = true; | |
| } | |
| </script> | |
| <body onload="runTest()"> | |
| <input type="checkbox" id="checkbox" checked> | |
| </body> | |
| </html> |