Release 10.1A: OpenEdge Development:
Progress 4GL Handbook

Object positioning

To arrange objects in a frame, you must explicitly position each one by setting the appropriate vertical (ROW or Y) and horizontal (COLUMN or X) attributes. However, Progress does assume the topmost and leftmost position in the frame if you do not set a placement attribute for the object. This means that, if you place multiple dynamic objects into a frame without positioning them properly, they all wind up on top of one another.