What should i do? thanks. (install fcitx)

After "./configure prefix=/usr" and "make" ,
the step:"make install eroo:

# make install
Making install in doc
make[1]: Entering directory `/usr/fcitx-3.6.2/doc'
make[2]: Entering directory `/usr/fcitx-3.6.2/doc'
make[2]: Nothing to be done for `install-exec-am'.
test -z "/usr/share/fcitx/doc" || .././install-sh -c -d "/usr/share/fcitx/doc"
/bin/sh: .././install-sh: Permission denied
make[2]: *** [install-docDATA] Error 126
make[2]: Leaving directory `/usr/fcitx-3.6.2/doc'
make[1]: *** [install-am] Error 2
make[1]: Leaving directory `/usr/fcitx-3.6.2/doc'
make: *** [install-recursive] Error 1

/bin/sh: .././install-sh: Permission denied