<p>
  <label>
    <input id="check-box" name="b" value="1" type="checkbox" disabled /> Check
    this box!
  </label>
</p>
<p>
  <label>
    <input id="toggle-box" name="b" value="2" type="checkbox" /> Enable the
    other checkbox.
  </label>
</p>

const checkBox = document.getElementById("check-box");
const toggleBox = document.getElementById("toggle-box");

toggleBox.addEventListener(
  "change",
  (event) => {
    checkBox.disabled = !event.target.checked;
  },
  false,
);