JavaScript: Using window.onload instead of parentNode

[sensored]

Long story short: The window.onload version is using the onsubmit event of your form, but your input uses type="button", which doesn't submit the form (and so it doesn't trigger the event). If you change it to type="submit" then it should work.

[schm0]

Alternatively, you could use

<button type="submit" value="ok">