注册时出错，系统自动退出！

[hfeeki]

canku/routes/user.js:112
if (!err & user.length > 0) {
^
TypeError: Cannot read property 'length' of undefined
at exports.register (/home/michael/repos/nodejsprojects/canku/routes/user.js:112:30)
at Object.exports.error (/home/michael/repos/nodejsprojects/canku/node_modules/mongoskin/lib/mongoskin/utils.js:27:5)
at EventEmitter.exports.bindSkin.obj.(anonymous function) (/home/michael/repos/nodejsprojects/canku/node_modules/mongoskin/lib/mongoskin/utils.js:66:17)
at EventEmitter.g (events.js:192:14)
at EventEmitter.emit (events.js:99:17)
at SkinCollection.open (/home/michael/repos/nodejsprojects/canku/node_modules/mongoskin/lib/mongoskin/collection.js:114:31)
at EventEmitter.g (events.js:192:14)
at EventEmitter.emit (events.js:99:17)
at null. (/home/michael/repos/nodejsprojects/canku/node_modules/mongoskin/lib/mongoskin/db.js:99:22)
at SkinDb.open (/home/michael/repos/nodejsprojects/canku/node_modules/mongoskin/lib/mongoskin/db.js:110:11)