// add Image
func (this *FileService) AddImage(image info.File, albumId, userId string, needCheckSize bool) (ok bool, msg string) {
	image.CreatedTime = time.Now()
	if albumId != "" {
		image.AlbumId = bson.ObjectIdHex(albumId)
	} else {
		image.AlbumId = bson.ObjectIdHex(DEFAULT_ALBUM_ID)
		image.IsDefaultAlbum = true
	}
	image.UserId = bson.ObjectIdHex(userId)

	ok = db.Insert(db.Files, image)
	return
}