NAME
	Exists

    SYNOPSIS
	Exists -determine, if a file exists - Requires v37

    INPUTS
	FILE/A,NAME/S

    FUNCTION
	Exists gets a filename and outputs if it exists.

	The resulting string is sent to STDOUT.

    RESULT
	if NAME is set the filename if the file exists,
	or empty string if not else 1/0

    NOTES
	CLI - only

	should compile with SAS-C

    BUGS
	We use 'Lock' to check the fil, so an exclusively
	locked file is not recognized.

    EXAMPLES
	>Exists Sys:
	1

	>Exists c:copy NAME
	c:copy

	>Exists jabba:the:hutt
	0

    AUTHOR
	Bernd Noll, Brunnenstrasse 55, D-67661 Kaiserslautern
	noll@student.uni-kl.de