Submit form using a button outside the <form> tag

Question

Say I have:

Answer 1

Maybe this could work, but I don't know if this is valid HTML.

<form method="get" action="something.php">
    <input type="text" name="name" />
    <input id="submitButton" type="submit" class="hide-submit" />
</form>

<label for="submitButton">Submit</label>