[azstar]

First of all, I think that what you are saying is that you did not have a specific seat assignment (e.g. a seat number) when you got to the airport. If the flight were overbooked, there are federal guidelines that apply about who is denied boarding and the compensation involved. If the flight were overbooked they are not allowed to deny boarding simply because someone does not have an assigned seat. US Air is notorious for doing this, and frankly, that is against the federal guideline. First, airlines must ask for volunteers. If they get no volunteers, they must deny boarding to the last person(s) who checked in. You should file a complaint with the Department of Transportation.