undefined reference to `activemq::library::ActiveMQCPP::initializeLibrary()'

Hi,
After I install the activemq-cpp package in my ubuntu successfully, I tried
to compile one example(src/examples/consumers/SimpleAsyncConsumer.cpp). But
I encountered errors bellow:

justin [ at ] justin-vaio:~/Programming/Mule/ActiveMQ-CPP$ g++ -I
/usr/local/include/activemq-cpp-3.8.2 -I /usr/local/apr/include/apr-1 -L
/usr/local/lib -L /usr/local/apr/lib -o a.o SimpleAsyncConsumer.cpp
/tmp/cclOhqV5.o: In function `main':
SimpleAsyncConsumer.cpp:(.text+0x10): undefined reference to
`activemq::library::ActiveMQCPP::initializeLibrary()'
SimpleAsyncConsumer.cpp:(.text+0x15): undefined reference to
`activemq::library::ActiveMQCPP::shutdownLibrary()'
collect2: ld returned 1 exit status

Am I missing something？

Justin