how do you get past stage 15 on this is the only level?"?

I don't know who told you about 15 levels, but YA only has 7.

Y!A only has 7 levels.

Answer & vote your daily limits.

Level 2 starts at 250 points.

All levels can pick a best answer to questions they ask and can vote for best answer on others' undecided questions. Once you hit level 2 & get the ability to 'rate', the only difference in the levels is the daily limits on questions, answers, comments, votes, etc.

Levels 2 and up can 'rate' the answers of other Y!A users. Rating = giving Thumbs Up & Down to express your opinion of other peoples' answers. No points are involved (unless a best answer has TUs, then they get 1 point for each TU up to 50) in rating, and thumbs do not determine the Best Answer selection.

Hints:

answer your limit of questions each day (2 points each)

get an answer selected as best answer (10 points each)

pick a best answer for your question (3 points)

vote your limit of unresolved questions each day (1 point each)

you also get a point a day for signing in

each question costs 5 points, so ask sparingly

:o)

http://answers.yahoo.com/info/scoring_system

Click on your points score (next to your own avatar) to go to the Points Explanation page. That will tell you about all the different levels, how many points you need to reach each one, how to earn and spend points, and that kind of stuff. Checking that page doesn't cost you 5 points, like asking a question does.

well we have to vote each other as best answer over and over