When true, the control is generated with an image button that, when clicked by the user, will popup another screen by sending the active selection key (defined in the UIProject settings), after setting the cursor to this field.
When this property is true, the PopupTitle property will become visible, providing a way to set the Title and mousehover tiptext of the button; the PopupOnF4 property will become visible: when true, will enable the user to press the F4 key as an alternative to clicking on the image button.
