FUNCTION SL_TOPMARG()

  Short:
  ------
  SL_TOPMARG() Designates the number of lines of top margin

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

  Syntax:
  -------
  SL_TOPMARG(nLines)

  Description:
  ------------
  Designates the number of lines of top margin <nLines>

  Examples:
  ---------
   ?SL_TOPMARG(3) // sets top margin to 3

  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