Breaking of mirror = Unlucky?

I remembered this one, It's a funny thing about a breaking of mirror.. They told me that when you break a mirror.. it's unlucky and if u look at yourself to a broken mirror.. You'll be ugly for 9 years.. WTF.

From what I have learnt. Mirrors are doorways into the other world. Mirrors act as crossings for demons,spirts,ghost whatever you can think off. So I always though breaking one would be a very good thing. With certain supernatural enterties, mainly demons, when an excoist is formed if you hang the mirror over the persons body, the demon can be trapped inside the mirror and then the mirror is to be smashed. Of course that could go wrong as the demon could infact smash the mirror which you put the possesed person in more danger.

However I found out that according to ancient beliefs, a mirror reflected the entity of your soul and when you stare at a mirror, you stare not only at your physical body, but your soul as well. When you break a mirror, you are basically "breaking your soul" and therefore, condeming yourself to 7 years of bad luck while your soul tried to repair itself and return to your body.