FUNCTION PRNPORT()

  Short:
  ------
  PRNPORT() Determine Printer Port to use

  Returns:
  --------
  <cPort> => port chosen

  Syntax:
  -------
  PRNPORT([cPort1],[cPort2]..[cPort9])

  Description:
  ------------
  Allows user to select printer port for SET PRINTER TO
  output. Printer is set to this port

  [cPort1-9] are valid SET PRINTER TO strings

  LPT1 LPT2 LPT3 COM1 COM2 COM3 COM4 <FILENAME>

  Default is "LPT1","LPT2","LPT3"

  Examples:
  ---------
   cTheport := PRNPORT("LPT1","COM1")

  Source:
  -------
  S_PRNPOR.PRG