Brian,
Thanks. Here is the output from Eclipse:
make -k all
Building file: ../main.cpp
Invoking: GCC C++ Compiler
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d"
-o"main.o" "../main.cpp"
Finished building: ../main.cpp
Building target: TestGSL.exe
Invoking: GCC C++ Linker
g++ -o"TestGSL.exe" ./main.o
./main.o: In function `main':
/cygdrive/f/CPP/TestGSL/Debug/../main.cpp:7: undefined reference to
`_gsl_sf_bessel_J0'
collect2: ld returned 1 exit status
make: *** [TestGSL.exe] Error 1
make: Target `all' not remade because of errors.
Build complete for project TestGSL
Lee.