I would have deleted the old thread but someone had already posted a reply and I didn't want to lose the reply. So I decided to merge the threads, then I would delete the original post. I tried several times and no matter how I did it, the original post remains as the thread starting post, so I cannot delete it.
How can I merge posts in such a manner as to choose which post will be the original post? No matter which thread I choose in the drop down box as the Destination Thread, the oldest thread is always the first post, and the other thread is merged into it.