The STRETCH attribute specifies how a widget must resize when the parent container is resized.
STRETCH = { NONE | X | Y | BOTH }
This attribute is typically used with form items that can be re-sized like IMAGE. TEXTEDIT, or WEBCOMPONENT fields. By default such form items have a fixed width and height, but in some cases you may want to force the widget to resize vertically, horizontally, or in both directions.
IMAGE i01 = FORMONLY.image01, STRETCH=BOTH;