NodeJS安装后可以执行命令，但无法执行文件
例如在命令行输入nom server.js执行server.js文件时会出现以下提示：
Usage: npm
where is one of:
access, adduser, bin, bugs, c, cache, completion, config,
ddp, dedupe, deprecate, dist-tag, docs, doctor, edit,
explore, get, help, help-search, i, init, install,
install-test, it, link, list, ln, login, logout, ls,
outdated, owner, pack, ping, prefix, profile, prune,
publish, rb, rebuild, repo, restart, root, run, run-script,
s, se, search, set, shrinkwrap, star, stars, start, stop, t,
team, test, token, tst, un, uninstall, unpublish, unstar,
up, update, v, version, view, whoami
npm -h quick help on
npm -l display full usage info
npm help search for help on
npm help npm involved overview
Specify configs in the ini-formatted file:
C:\Users\Administrator.cnpmrc
or on the command line via: npm --key value
Config info can be viewed via: npm help config
npm@5.5.1 C:\Users\Administrator\AppData\Roaming\npm\node_modules\cnpm\node_modules\npm
有哪个大神指导，请指点以下，怎么操作可以让他执行JS文件，是因为什么引起的
