How to move between panels?

[josharmenta]

I'm sorry for the basic question but I'm doing something wrong.

I have panel-a and panel-b. panel-a contains a button which is supposed to transition to panel-b. The function works to hide panel-a but doesn't bring up panel-b. I can run create-panel-b in isolation fine, but it's not working as part of this function:

(defun nav-button-clicked (panel)
    (setf (hiddenp panel) t)
    ;; Replace it in the center with panel B
    (let* ((panel-b (create-panel-b
      (parent-element panel))))))

Can anyone tell me what I'm doing wrong?