Mingw Compiling Error

[Hal Lorenz <heuristic gmail com>]

Hi there,

I'm following the docs (slowly ;) but can't seem to compile the files here:
http://www.gtkmm.org/docs/gtkmm-2.4/examples/book/helloworld/

Compiler options:
g++ main.cc -o program `pkg-config gtkmm-2.4 --cflags --libs`

Compiler error:
C:/DOCUME~1/Alex/LOCALS~1/Temp/ccgvbaaa.o(.text+0x1aa):main.cc:
undefined reference to `HelloWorld::HelloWorld()'
C:/DOCUME~1/Alex/LOCALS~1/Temp/ccgvbaaa.o(.text+0x1d4):main.cc:
undefined reference to `HelloWorld::~HelloWorld()'
C:/DOCUME~1/Alex/LOCALS~1/Temp/ccgvbaaa.o(.text+0x233):main.cc:
undefined reference to `HelloWorld::~HelloWorld()'
collect2: ld returned 1 exit status

I can compile the simple windows fine... any ideas?

Kind regards,
Hal Lorenz