NAME: 
  tobacksl
 PURPOSE:
  Convert forward slash (/) to backslash ($\backslash$) in string.
 DESCRIPTION:
 CATEGORY:
  Utility
 CALLING SEQUENCE:
  str=tobacksl(str)
 INPUTS:
  str - String to scan and convert
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
  return value is a copy of the string with / converted to \\
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  96/01/21, Written by Marc W. Buie