I've checked a few pages online on how to disable a submit button of a dropdown box unless an option has been selected. But can't find one that works for me. Any help on how to do that would be great!
Edit: I don't want <option value="not_valid">-- select an option --</option> to be considered as an option
<form action="action_page.php">
<select name="attacks" id="attacks">
<option value="not_valid">-- select an option --</option>
<option value="attack1">1</option>
<option value="attack2">2</option>
<option value="attack3">3</option>
<option value="attack4">4</option>
<option value="attack5">5</option>
</select>
<br>
<input type="button" id="battle" onclick="game()" value="Battle">
</form>