How to make this simple code to IF / ELSE argument for PHP

Here’s the code, and I need to know how to make it an IF/ELSE argument. Is that possible? Thanks for any help you have.

<li class="<?php if (1 == $comment->user_id) $oddcomment = "authcomment";
echo $oddcomment; ?>" id="comment-<?php comment_ID() ?>">
<li class="<?php if (1 != $comment->user_id) $oddcomment = "othrcomment";
echo $oddcomment; ?>" id="comment-<?php comment_ID() ?>">