Link to Child Document - Can't Solve - Please Help

I have a document containing seven or more children. What I want to do is insert a link (like "back" or "next") that will link to the next sequential child document.

The problem I have is that if I create a hard link from page [~3~] to page [~4~], and then decide that page [~6~] needs to be arranged in-between 3 and 4, I have to re-link everything. Breadcrumbs would work, but they show the entire menu structure.

I need the separate pages to behave like pages in a gallery. And the links within the pages recognize where they are in the menu structure and adjust accordingly.

Anyone have any ideas?

Yes, the PrevJumpNext snippet is just what you need. http://modxcms.com/extras/package/351