<input style=width:100% autocomplete=off id=url><br>

<select id=mode> 

  <option value=none>No security</option>

  <option value=blacklist>Blacklist</option>

  <option value=whitelist>Whitelist</option>

</select>

<hr>

<h2>Profile page</h2>

<p>My profile page url: <a id=addr></a></p>

<script>

  url.oninput = mode.onchange = ev => {

    let u = url.value;

    let m = mode.value;

    if (m === 'blacklist') {

      if (u.match(/^\s*javascript:/i)) {

        u = 'unsafe:' + u;

      }

    } else if (m === 'whitelist') {

      if (!u.match(/^https?:\/\//i)) {

        u = 'unsafe:' + u;

      }

    }

    addr.href = addr.textContent = u;

  }

</script>