Nested database loops and completing an unordered list....

Good morning PHP groupies! I am working on this tool that will ultimately display a collapsible org chart. The org chart is based on a nested unordered list and that is the heart of my question. The NUL(nested unordered list) is based on a set of database queries - sometimes as many as 14 queries. Each query relies on data returned by all of the the queries before it. So what I am doing right now is this - query generates a list item

    while this list item get the next level dependent upon this item
        query generates this list item
                while this list item get the next level dependent on each list item above

...and so on. (I have written about this before and thought I had it solved, but alas, that is not the case.) The result needs to be something like this: <ul> <li>level a <ul> <li>level b</li> // has no children <li>level b <ul> <li>level c</li> </ul> </li> </ul> </li> </ul> This is a semantically and syntacticallycorrect UL. Keep in mind that this can go many levels deeper. The hardest part, and the part that I am looking to accomplish, is closing the list items properly regardless of how deep the tree is. If properly handled this could even be made into JSON with the proper syntax, but I am not worried about that now. I was hoping that a fresh set of eyes would point me to a solution that I obviously cannot see at the moment. Thanks! Jay