On my post about the submenu bar, I had a question about dropdown menus, but at the time I couldn’t answer.
I most cases, getting dropdown menus to work should be pretty easy, although there are a lot of posts on various forums from people having difficulty. The reason I was having trouble getting it to work earlier was I had modified my css files for other reasons, and accidentally wiped out important parameters.
The instructions for making the dropdown menus work in ja_purity are in various places, including a post on Learn Web Design Online.com . But if you read that post and are still lost, you may have to back up and learn how to make the sub-menus in the first place. Those instructions are at Joomla’s documentation site.
Having the dropdown menus along with the submenu bar means maintaining two separate sets of submenus. I don’t see any way to link them automatically. One set of submenus are the dropdowns, which you create by the instructions that I mentioned in the previous paragraph, and one set of submenus are the menus that appear in the sub-menu bar, which you create in accordance with my post (linked in the first paragraph). Any changes you make have to made in both.