Tsearch2 doesn't work

Hi,

I want to install Tsearch2 and follow  this command :
1.cd contrib/tsearch2
2. make; make install

It doesn't work and display this messages :
Makefile:5: ../../src/Makefile.global: No such file or directory
Makefile:47: /contrib/contrib-global.mk: No such file or directory
make: *** No rule to make target `/contrib/contrib-global.mk'.  Stop.
Makefile:5: ../../src/Makefile.global: No such file or directory
Makefile:47: /contrib/contrib-global.mk: No such file or directory
make: *** No rule to make target `/contrib/contrib-global.mk'.  Stop.

What it's means? What should I do? Please help me.

Thanks.