Setting Up Gadget Docking: <fgdock>

The DOCK attribute allows you to dock a gadget to the left, right, top, or bottom edge of its container, typically a form or a frame; or you can cause the gadget to dock to all edges, or to no edges.

>-- <fgdock> -----------+-- DOCK ----+-----Left ----.

                                     +---- Right ‑--|

                                     +---- Top -----|

                                     +---- Bottom ‑-|

                                     +---- None --‑-|

                                     ‘---- Fill --‑-’-->

Note:
The DOCK and ANCHOR attributes are mutually exclusive.
Setting the DOCK attribute resets the ANCHOR to the default; setting the ANCHOR attribute resets DOCK to none.
You can set these attributes only when you define the gadget: you cannot change it after the exit from form setup. Thus you are not allowed to the resize behavior at run-time.