Unlock (21)
         +-----------------------------------------------------------------+
         | Operation| Position |DataBuffer| DataBuff |    Key   |    Key   |
         |          |  Block   |          |  Length  |   Buffer |   Number |
 +-------+----------+----------+----------+----------+----------+----------|
 |Expects| BT_UNLOCK|    X     | Address  |    4     |          |     X<---+-+
 |-------+----------+----------+----------+----------+----------+----------| |
 |Returns|          |          |          |          |          |          | |
 +-------------------------------------------------------------------------+ |
                                                                             |
Unlocks one or all locked records            +---------------------------+   |
                                             | 0 Single Record Lock vv   |   |
Address and Length are only used with        |-1 Multiple Lock at Address|---+
-1, Address is obtained with the             |-2 All Multiple Locks      |
Get Position operation.                      +---------------------------+




Current Position: No effect