You can only place form objects within a Layout Region of a Multi Layout Region.
You cannot place a form object directly on a Multi Layout Region.
By enabling the Forms check box from the Multi Layout Region Properties panel, you designate the Multi Layout Region as a form area. All the Layout Regions that it contains will inherit this attribute.
If you check the Form option from the Multi Layout Region Properties panel, you may add form objects on any Layout Region that is placed within the Multi Layout Region.
If you check the Form option from the Layout Region Properties panel, you may add form objects only on the selected Layout Region.
To designate a Multi Layout Region as a form area:
Display the General section of the Multi Layout Region Properties panel.
Check the Form option.
The Form Toolbar appears and the Multi Layout Region becomes a form area in which you may place multiple Layout Regions that also behave as form areas.
You can add any standard form objects to a form area, including single- and multiple- line text fields, check boxes, radio buttons, scrolling lists, and drop-down lists.
For more information, see Designing and Implementing Forms.