Liquid Layout built with layers/ap-divs?

Hi there,

this is probably a stupid question but is it possible to build a liquid layout website in DW CS4 by solely using layers (now called ap-divs)? Or do I have to use tables and columns because images inserted in ap-divs are always static?
( I would like to use a logo at the head of my website which always stays in the middle of the site )

thank you very much for your help,
alice

ps: please excuse my english / the question. I´m not a native speaker and a newbie to DW also.