Tabs are used to create Tabbed dialogs like the ones used in the Map Editor itself.
You need to do the following to make good use of Tab controls:
Create a map containing OK and Cancel buttons, a 3D static control in 'Inverted data map' colours and Tab buttons for each of the tabs in the page control. The tabs should be positioned so that they are all on the same horizontal position, all the same depth, all immediately adjacent and are immediately above the 3d static control. The 3d static control should be large enough to enclose the maps used to implement each page. Include a hook just inside the static control for attaching these maps. Make sure this map has an activating function key. F1 will be a good choice.
Associate a different field number with each tab (it will be best to number them consecutively starting from 2). You can also optionally associate function keys, such as F2 and F3, with each tab, although this is not necessary; each tab can be mapped to the Enter key. Code your C application or QAB program to display the appropriate map for the Tab when it receives the option/function key value associated with the Tab.
Create the maps for each page. Each map should have an activating function key that is the same as the option to which it corresponds in the Tabs. For example, the leftmost Tab's dialog will normally have F2.
You can use the Add Tabs dialog to slightly simplify creating a set of maps for a Tabbed dialog.