I have tp stop spam on my blog! Please help!

Hi all,
i’ve got a blog made all by myself and i created an asp page for the comments but i dont know how to stop spam comments…

I would like to create a register and login area with confirmation email to try stop this (but really i dont know if this could help or its an inuseful work).

Please i have to stop this,
i receive messages every 3 hours.

Many Thanks in advance.