status.i4.v = fm_unlock(vun.i2.r [,ext_status.i4.r])

	status.i4.v = fm_unlock_c(vun.i2.v [,ext_status.i4.r])

	This routine will unlock a Filesharing file opened on the virtual
	unit number.

	vun		virtual unit number on which the file was opened
	[ext_status]	returned extended status from VMS/RMS (default is NULL)

	This function returns ACNET status values as follows:

	OK			success
	FSHARE_xxx		error unlocking the file

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	fm_read(_c), fm_write(_c)

	C/C++ usage:

	short	vun;
	int	status;
	int	ext_status;

	status = fm_unlock_c(vun,&ext_status);