评论框勾选一个checkbox后才能提交评论

<label for="checkcomment">

<input type="checkbox" value=9 id="checkcomment" name="checkcomment" required autocomplete="on" required title="发表评论确认框：请勾选我再发表评论！">

<font color="red">请勾选我再发表评论！</font>

</label>