Installing problem with aim

[D D]

I installed aim by going to /usr/ports/net/aim and then typing make
install clean.  The install seems to go through successfully but when
i try to run aim by typing aim in the shell, i get the following
error.

root@# aim
/usr/X11R6/libexec/aim: error while loading shared libraries:
libXprt.so.1: cannot open shared object file: No such file or
directory

I am running freebsd 6.0 and am pretty new at it so this might be a
simple problem, but i have no idea what it means.

Thanks for helping