PopUpMenu -- Overview
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 Class Function

 PopUp()         Create a new PopUp object
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 Exported Instance Variables

 border          An optional string used when drawing the menu's border
 bottom          A numeric value indicating bottommost screen row
 cargo           User-definable variable
 colorSpec       Display attributes string
 current         Numeric value indicating the selected item
 itemCount       Numeric value indicating the number of items in the object
 left            Numeric value indicating the leftmost screen row
 right           Numeric value indicating the rightmost screen row
 top             Numeric value indicating the topmost screen row
 width           Numeric value indicating width requirements
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 Exported Methods

 addItem()       Appends new item to pop-up menu
 close()         Deactivates a pop-up menu
 delItem()       Removes an item from a pop-up menu
 display()       Shows a pop-up menu including its items on the screen
 getAccel()      Determines if a key press is interpreted as a user request
 getFirst()      Determines position of first selectable item in a menu
 getItem()       Access a MenuItem object after it has been added to a menu
 getLast()       Determines position of last selectable item in a menu
 getNext()       Determines position of next selectable item in a menu
 getPrev()       Determines position of previous selectable item in a menu
 getShortct()    Determines if a key press is interpreted as a user request
 hitTest()       Indicates position of mouse cursor relative to pop-up menu
 insItem()       Inserts a new item to a pop-up menu
 isOpen()        Determines if a pop-up menu is open
 open()          Activates a pop-up menu
 select()        Changes the selected item
 setItem()       Replaces a MenuItem object after it has been added to a menu