I have made a email form in DW and want to make some of the fields to be REQUIRED so visitors will have to fill in, in order to sign up.

How I can do it? Thank you!

Required form fields are processed by your formamail (or similliar) script.

You'll need to add something like this to the code of your form:

<input type="hidden" name="required" value="LastName, FirstName" />

sounds like you need the yaromat form validation extension for dreamweaver
it validates all sorts of items
yaromat.com
you simply install it using the dreamweaver extension manager and yaromat form validation will do the rest

hth

craig