get a result express node.js mongodb

I can't get a result from a mongoDb, see my code

//connect user
getUser = function(login, password, callback){
    models.user.find({
        password: global.helper.encode(password),
        $or : [ {
            username : login
        } , {
            mail : login
        } ] 
    },function(err, result){
        console.log(result)
        console.log(result.username)
        callback(result);
    })
}

console.log(result) return :

[ { username: 'ant',
mail: 'aa@aa.aa',
password: '7e240de74fb1ed08fa08d38063f6a6a91462a815',
date_register: Sun, 18 Nov 2012 11:58:45 GMT,
date_login: Sun, 18 Nov 2012 11:58:45 GMT,
_id: 50a8cd75494a6db815000001,
__v: 0 } ]

and console.log(result.username) return undefined

I also try result['username'] but I have undefined too

thanks for your help