Prototype CSS selector to descend tree?

Hi, I'm calling on those with Prototype/CSS selector foo to help with a somewhat tricky issue.

I have a tree structure where each item is hierarchical. This is used to manage software components. Think of the case where you're installing a piece of software, and want to customize which packages are installed:

Internet      Email          Thunderbird          Evolution          Outlook Express      Browsing          Firefox          Internet Explorer    Entertainment      Music          iTunes          Winamp

In this menu, if the user clicks on a given checkbox, I want all sub elements to check as well (and the same on uncheck, obviously).

Since there are all simple checkboxes, I tried attaching this function to onclick:

   function toggle_children (input) {     // locate "input#myid input" (all children)     $$('input#'' input').each(function (item) {         if ( !== {           item.checked = input.checked;         }     });   }

But unfortunately, that did not select the elements. The pure CSS selector that should work is:

   input#myid > input

However, unfortunately passing that to Prototype gives "error parsing selector at: > "


Thanks, Nate