Port reinstall

[funtik]

Hello All!!
I cann`t reinstall port if package already present at the system!!

example:

cd /usr/ports/devel/libtool14 && make reinstall

This compiled but return next message:

Making all in tests
===>  Installing for libtool-1.4.3_3
===>   Generating temporary packing list
===>  Checking if devel/libtool14 already installed
===>   An older version of devel/libtool14 is already installed 
(libtool-1.4.3_2)
      You may wish to ``make deinstall'' and install this port again
      by ``make reinstall'' to upgrade it properly.
      If you really wish to overwrite the old port of devel/libtool14
      without deleting it first, set the variable "FORCE_PKG_REGISTER"
      in your environment or the "make install" command line.
*** Error code 1

Stop in /usr/ports/devel/libtool14.
*** Error code 1


What point?

Thanks!