The way your comment is worded is perfectly fine. In fact, it has been previously covered by [Marco Ceppi][1]:

> As for nudging the user, there is nothing wrong with leaving a comment on the question requesting the author select an answer - or improve their original question if it's still unanswered.

Not every single new user on the site knows how Ask Ubuntu works, so giving the user suggestion ( and only a suggestion, not direct push as in "Accept mine and only mine" ) is perfectly ok.


  [1]: http://meta.askubuntu.com/a/1520/295286