Make this layer unavailable for other tasks to use. If another task is already using this layer then wait for it to complete and then reserve the layer for your own use.
    This function does the same thing as 
graphics.library/LockLayerRom()
    
      - Note: 
- 
        if you wish to lock MORE THAN ONE layer at a time, you
 
 
    must call 
LockLayerInfo() before locking those layers and then call 
UnlockLayerInfo() when you have finished. This is to prevent system "deadlocks".
    Further Note: while you hold the lock on a layer, Intuition will block on operations such as windowsizing, dragging, menus, and depth arranging windows in this layer's screen.  It is recommended that YOU do not make Intuition function calls while the layer is locked.