Fields on Kentico Blog Adding Comments form

Hello. I created a standard Kentico blog on a site I'm working on, and on the form for adding comments I have a name, email, url and comments fields, together with a captcha. Do you know where I can set what fields to be displayed in this form? I want to get rid of the "Your URL" field (which is not mandatory anyways), but I can't find it. I did some search on the Internet, but I didn't find specifically this information. I know that the email and captcha fields are set from the blog properties.