If you are doing a table based layout, you can set your table width to a percentage instead of pixels. That will allow your layout to stretch with the browser as it is resized. Designers generally called that a "liquid" layout.
But if you're building a new site in Dreamweaver, you should consider controlling your layout with cascading style sheets (css) instead of tables. You can still create a layout that will stretch with the browser size if you like those types of sites.
Adobe has a pretty good introduction for using Dreamweaver to create a design without tables at the bottom of this page:
http://www.adobe.com/devnet/dreamweaver/
But if you're building a new site in Dreamweaver, you should consider controlling your layout with cascading style sheets (css) instead of tables. You can still create a layout that will stretch with the browser size if you like those types of sites.
Adobe has a pretty good introduction for using Dreamweaver to create a design without tables at the bottom of this page:
http://www.adobe.com/devnet/dreamweaver/
