Gaps between cells when previewing in browser
In dreamweaver

Preview in browser

Hi all,
I am just messing about with dreamweaver (hence excuse the design) and I am not sure why this is happening, but on dreamweaver I have created a table (800w) with 3 rows. On the top row I have a banner, in the next a nav bar and the 3rd row is an editable region. But as you can see in dreamweaver there are no white gaps at the top of the banner or in between the banner and nav bar. However when previewing it on the browser there is a white gap at the top of the banner and nav bar. Not sure how to fix this, please help!
Thanks in advance.
