How to add comment box to my web site ….?

This is my web site http://www.thecashcollector.com/
I want to add comment box to it …. now i have add comment box but i got that code in a internet (http://www.zimmertech.com/tutorials/php/25/comment-form-script-tutorial.php)

It has more problem.
1.It is not allow HTML code ….
2.It support BB code …(i want to remove it )

Please tell anyone know about web design .. how to make this type of comment box

http://psdfan.com/tutorials/designing/design-a-professional-portfolio-web-layout/

give me step by step …..