No package 'gtkmm-2.4' found

[Kathrin Hauptvogel <hauptvogel k rheinmetall-de com>]

Good morning at all.

I have a question because I can't compile the "hello world example" from this 
site. 
After entering this command

# g++ main.cc -o main `pkg-config gtkmm-2.4 --cflags --libs`

this text is standing on my console. 

Package gtkmm-2.4 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gtkmm-2.4.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gtkmm-2.4' found
main.cc:1:24: gtkmm/main.h: No such file or directory
In file included from main.cc:2:
helloworld.h:4:26: gtkmm/button.h: No such file or directory
helloworld.h:5:26: gtkmm/window.h: No such file or directory
In file included from main.cc:2:
helloworld.h:7: error: `Gtk' is not a class or namespace
helloworld.h:8: error: `Window' is not a class or namespace
helloworld.h:8: error: invalid base-class specification
helloworld.h:19: error: syntax error before `::' token
main.cc: In function `int main(int, char**)':
main.cc:6: error: `Gtk' undeclared (first use this function)
main.cc:6: error: (Each undeclared identifier is reported only once for each
   function it appears in.)
main.cc:6: error: syntax error before `::' token
main.cc:9: error: syntax error before `::' token

what should I do?