purge(options: String): Integer;
The purge method of the JadeGenericQueue class discards all messages in the queue that have not been retrieved and returns the number of discarded messages.
Use this method to purge an existing queue of reply messages before issuing another request.
For the options parameter, no generic or transport-specific options have been defined, so you should pass a null string, as shown in the following code fragment.
myQueue.purge(null);