lock, call <CODE>
MemUnlock()</CODE>
, passing the handle of the block to be unlocked. <CODE>
MemUnlock()</CODE>
 decrements the lock count.</P>
<P>
A block may be locked by any of the threads run by its creator; if the block is sharable, it may be run by any other thread as well. There is nothing in the <CODE>
MemLock()</CODE>
 routine to prevent different threads from locking a block at the same time, causing potential synchronization problems. For this reason, if threads will be sharing a block, they sho