Forum Moderators: mack
If not, you have left it up to the search engines to list the www- or non-www domain as they choose, or worse -- to split your PageRank or Link Popularity across both domains, thus lowering your ranking in either.
There are many threads here on redirecting non-canonical URLs to canonical URLs. The best title so far is "Duplicate content -- Get it right or perish," which about sums it up...
Jim