npm install fails on Ubuntu

[xavierzhao]

Here's my console output:
npm http GET https://registry.npmjs.org/tedious
npm http 304 https://registry.npmjs.org/tedious
npm http GET https://registry.npmjs.org/async/0.1.22
npm http GET https://registry.npmjs.org/iconv-lite/0.2.4
npm http GET https://registry.npmjs.org/sprintf/0.1.1
npm http 304 https://registry.npmjs.org/iconv-lite/0.2.4
npm http 304 https://registry.npmjs.org/sprintf/0.1.1
npm http 200 https://registry.npmjs.org/async/0.1.22
npm http GET https://registry.npmjs.org/async/-/async-0.1.22.tgz
npm http 200 https://registry.npmjs.org/async/-/async-0.1.22.tgz
npm ERR! addPlacedTarball Could not remove "/home/xavierzhao/.npm/async/0.1.22/package"
npm ERR! Error: EACCES, unlink '/home/xavierzhao/.npm/async/0.1.22/package'
npm ERR! { [Error: EACCES, unlink '/home/xavierzhao/.npm/async/0.1.22/package']
npm ERR! errno: 3,
npm ERR! code: 'EACCES',
npm ERR! path: '/home/xavierzhao/.npm/async/0.1.22/package' }
npm ERR!
npm ERR! Please try running this command again as root/Administrator.

npm ERR! System Linux 3.5.0-25-generic
npm ERR! command "nodejs" "/usr/bin/npm" "install" "tedious"
npm ERR! cwd /home/xavierzhao/Documents/workspace/lenovoctd/04.SRC/01.trunk/03.InstantConnect/server/nodejs
npm ERR! node -v v0.8.22
npm ERR! npm -v 1.2.14
npm ERR! path /home/xavierzhao/.npm/async/0.1.22/package
npm ERR! code EACCES
npm ERR! errno 3
npm ERR! stack Error: EACCES, unlink '/home/xavierzhao/.npm/async/0.1.22/package'
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR! /home/xavierzhao/Documents/workspace/lenovoctd/04.SRC/01.trunk/03.InstantConnect/server/nodejs/npm-debug.log
npm ERR! not ok code 0

My Node is v0.8.22 and my NPM is v1.2.14

[xavierzhao]

Sorry, file permission issues