Folder prev. next Navigation - BasicNav???

Hi!
I'm trying to build a folder navigation with prev. next links. I want to have something like cursor keys of the end of each document that link to the next or prev. document in a certain folder. I found the snippet BasicNav but this doesn't output anything. I set placeholder to 0 but the only output i get is for my root (home) document something like "no parents?". I also tried selfLink but this is just creating a navigation by id so this is pretty useless for me.
Could anyone help me? Would be great.

it looks like selfLink doesn't set placeholders, so even though you can indicate a template chunk, you can't actually create one that's useful. There were several useful snippets under Evo... sigh.

hmmm - so there is no solution for a simple prev. next navigation in folders in revo? hmmm... why is basicnav not outputting anything? Has anyone any hints for me?

I found this:
http://forums.modx.com/index.php/topic,59000.msg357995.html#msg357995
and now basicnav seems to work fine for me.
The only thing that is missing, is that i cannot use it to start the navigation from the parent to go down to its child and then navigate in the folder... Maybe basicnav can be exapndet? .