Unfortunately because of the limitations with the rendering abilities of Dreamweaver and the dynamic properties of the forms you will need to preview them on a working server to get an idea of how they will look live. If you enter the access details into the testing server settings for your site in Dreamweaver though you can use DW's preview in browser (F12) functionality to automatically upload the page and browse to it.
This can be a big time saver if you need to do a lot of previewing of the pages you are creating.