NAME
	AttemptLockDosList -- Attempt to lock the Dos Lists for use (V36)

   SYNOPSIS
	dlist = AttemptLockDosList(flags)
	D0			    D1

	struct DosList *AttemptLockDosList(ULONG)

   FUNCTION
	Locks the dos device list in preparation to walk the list.  If the
	list is 'busy' then this routine will return NULL.  See LockDosList()
	for more information.

   INPUTS
	flags - Flags stating which types of nodes you want to lock.

   RESULT
	dlist - Pointer to the beginning of the list or NULL.  Not a valid
		node!

   BUGS
	In V36 through V39.23 dos, this would return NULL or 0x00000001 for
	failure.  Fixed in V39.24 dos (after kickstart 39.106).

   SEE ALSO
	LockDosList(), UnLockDosList(), Forbid(), NextDosEntry()