Test case : Increment/Decrement Window

Define a window IncDec containing three objects:

  Value:  defaults to 0; the user can enter any number.
  Increment:  a button; when pressed, Value is incremented by 1.
  Decrement:  a button; when pressed, Value is decremented by 1.

The arrangement of objects in IncDec is:

             Value
      Increment  Decrement