[Gnash] How to set the second boost library path? (Updated)

[new bee]

I have some problems in building gnash. I have compiled and installed a boost library using default setting as follows...

bjam  install

*****default directory*****
head files in /usr/local/include/boost-1_34/boost/
libs in       /usr/local/lib/.
**********

Now, I want to build another boost library in testing embedded environment, hoping it run in my testing environment.I use commands as follows...

bjam --prefix=/opt/workspace/host/common/build/opt   install

./configure --prefix=/home/newbee/flashplayer   --disable-plugin --disable-klash --with-boost-incl=/opt/workspace/host/common/build/opt/include/boost-1_34/  --with-boost-lib=/opt/workspace/host/common/build/opt/lib

Now, here is the problem:

when it runs, it still checks my boost library in /usr/local:
...
checking for boost header... -I/usr/local/include/boost-1_34
checking for Boost libraries... -L/usr/local/lib -lboost_date_time-gcc34-mt -lboost_thread
...
And finally it shows information:
        POSIX Threads flags are: -pthread
        POSIX Threads lib is: -lpthread
        This version of libCurl doesn't have RTMP support
        CURL flags are: default include path
        CURL libs are: -L/usr/lib -lcurl
        BOOST flags are: -I/usr/local/include/boost-1_34
        BOOST libs are: -L/usr/local/lib -lboost_date_time-gcc34-mt -lboost_thread
....

Can you tell me how to set boost library path to /opt/workspace/host/common/build/opt/?

Thanks a million!