Mark thread as answered / resolved

I logged a question and then, because of the time zone delay, found the answer nyself.  How do I mark this thread as answered?

If there is no feature can I suggest that there ought to be?  At least, in part, so that the forum users and monitors can keep a track of how many problems remain unresolved.

I haven't used this forum for a year (I got so frustrated with RonR that I gave up, thinking that in time things might improve) but I noticed before that if a question was not answered in the first 24 hours, it was never answered.  This resulted in frequent reposting of the same issue in the hope that it might catch the attention of ryanb or someone else with a good grasp of the issues.