Form API to create new labels or to change labels dynamically. 
 display a text or graphic label in a box. 
The default style for a button is a text string centered within a rounded rectangle. 
Buttons have rounded corners unless a rectangular frame is specified.
A button without a frame inverts a rectangular region when pressed.
| User Action | System Response |  CtlHandleEvent Response 
   | 
 
| Pen goes down on a button. | 
    penDownEvent with the x and y coordinates stored in EventType  | 
  Adds the ctlEnterEvent to the event queue. | 
   ctlEnterEvent with button's ID number
    | 
  Inverts the button's display. | |
| Pen is lifted from button. | 
    penUpEvent with the x and y coordinates stored in EventType
   
    | 
  Adds the ctlSelectEvent to the event queue. | 
| Pen is lifted outside button. | 
   penUpEvent with the x and y coordinates stored in EventType
   
    | 
  Adds the ctlExitEvent to the event queue. |