FUNCTION SL_SETCPI()

  Short:
  ------
  SL_SETCPI() Sets characters per inch

  Returns:
  --------
  cCode => control string to send to the printer

  Syntax:
  -------
  SL_SETCPI(nCPI)

  Description:
  ------------
  Sets characters per inch to <nCpi>  - valid to 2
  decimal places. Current font must support this CPI.

  Examples:
  ---------
   ?SL_SETCPI(16.66)   // sets to compressed

   ?SL_SETCPI(12)     // sets to 12 cpi

   ?SL_SETCPI(10)     // sets to 10 cpi  (default)

  Notes:
  -------
  Does not send anything to the printer - instead
  returns a control string that you send to the printer. String can be
  sent with ? or ?? or  QOUT() or QQOUT().

  For HP and compatible(PCL) Laserjet printers.

  Source:
  -------
  S_HPLAS.PRG