n specified; if there are, it will fail and return ERROR_ALREADY_LOCKED. If there are no locks, it will place a lock on the region specified and return zero.</P>
<P CLASS="refField"><STRONG>
Warnings:</STRONG>	Locking a region only prevents threads from locking part of the same region; it does not prevent them from reading from or writing to the region. If applications use this mechanism, they have to make sure to call <CODE>
FileLockRecord</CODE>
 before trying to access a part of a file.</P>
<P CLASS="ref