I don't think it can be done with just dreamweaver,
You will have to download something like PHPBB,
If you have a host with fantastico deluxe you can easily set up a forum
>I want to create a forum or messageboard using the
>form in Dreamweaver but I don't know how to do it.
You could probably build a crude messageboard using a SQL database and DW server behaviors, but it probably won't meet your needs. To build your own, you would need to become profient with database design, SQL, and server side scripting languages. In the end, it will take you a long time and is probably not worth it. Why not just use an pre packaged messageboard/forum product?
thats not what the Dreamweaver "FORMS" are for
Look at what you are typing and how its spelled
Dreamweaver makes "FORMS"
a messaeg board is a "FORUM"
do you notice the "U" in hte spelling
the FORMS created in dreamweaver are basically boxes, that you fill in with info
lke when you goto a site and put in all your user registration info
You have entered info into FORMS
a FORUM is a group gathering place where people discuss topics
the are completely different things
and no, its not practical to design a FORUM in dreamweaver