The "Report abuse" link shown by Hans-Günter should normally appear in the location he indicated. However, it refers to the whole thread (or the original post if there's only one post in the thread). To report individual posts as spam (or any other type of abuse), click the Report link at the top right of the post you want to report:
When several people (I think it requires three to do it) report the same post, it's automatically hidden from view. Even if only one person reports it, a moderator will usually see the report and take action very quickly. There are moderators in all parts of the world helping to combat spam, but it's an uphill battle.
I have seen the result of moderation here in the Adobe forums and I have to say they're quick and pretty efficient.
It's a pretty thankless task and I'm very appreciative. Keeps the Adobe forums very useful.