def add_comment(model_name,postid,data):
comment=Hifcomment();
comment.id=Id.get_next_id('commentid')
comment.content = data['content']
comment.author=Hifuser.objects.get(id=int(data['author_id']))
comment.save()
model = Model[model_name].objects.get(id=int(postid))
model.comments.append(comment)
model.save()
return True
