var siteSchema = new Schema({
    "company_url": {type: String, trim: true, index: true, unique: true, required: true, dropDups: true },
    "angellist_url": {type: String, trim: true },
    "product_desc": {type: String, trim: true },
    "blog_url": {type: String, trim: true },
    "video_url": {type: String, trim: true },
    "crunchbase_url": {type: String, trim: true },
    "name": {type: String, trim: true },
    "high_concept": {type: String, trim: true},
    "logo_url": {type: String, trim: true},
    "twitter": {type: String, trim: true},
    'user_favs': [{type: Schema.Types.ObjectId, ref: 'User'}],
    "feature_date": {type: Date},
    "active": {type: Boolean}
});

var site_id = req.params.site_id;
    Site.find({_id:site_id}, function(err, site){
        console.log(req.user_id);
        site.user_favs.push({_id: req.user._id});
        site.save( function(err, site_res){
            res.send([err,site_res]);
        });
    });