User-Interface Functions
  Overview        About these routines
  XPcolor()       Define the colors to use in the routines
  XPdisplay()     Display a string with more colors
  XPstrLen()      Get the length of a String for display
  XPaStrLen()     Get the length of the longest string in an Array
  XPinkeyBlock()  Define a new handler for key-strokes
  XPinkey()       Same as Clipper's Inkey() with the Handlers from above
  XPbox()         Draw a Titled box, with border and shadow.
  XPbox2()         Draw a Titled box, with broad border and shadow.
  XPalert()       The Alert function for this section
  XPask()         Pop up as box with a question and returns answer
  XPmenu()        A Menu Command
  XPboxMenu()     Invoke a simple Boxed menu
  XPcenter()      Center's a String.
  XPmsg()         Put a Message on the Bottom line
  XPpop()         Pop a Message on the Screen
  XPpushScr()     Push the Screen contents on a Stack
  XPpopScr()      Pop the Screen contents back on Screen
  XPpullInit()    Initialise the Pull Down Menu system
  XPpullMenu()    Invoke the Pull Down Menu System