class UserProfile(models.Model):
    user = models.OneToOneField(User) #extends user model
    phone_number = models.CharField(u'Number', max_length=20)

class TextMessage(models.Model):
    sender = models.ForeignKey(User)
    to = models.CharField(u'Number', max_length=20)
    message = models.TextField(null=True, blank=True)