Comments not being posted

I am brand spanking new to blogging and although I have a bit of HTML experience I still classify myself as a web amateur.

I have created a very quick blogging site by using a pre-written template. Seems to be working alright although I have had a few messages from people saying that they can not make a comment on the blogs. I have checked myself and it seems that you can write the comment and press submit but it just returns to the blog page, without posting the comment.

I am obviously doing something so obviously stupid but any guidance would be very gratefully appreciated