Border colour change?

Hi there, I am trying to change the main panel border so that there is no grey line around the site content. I kind of want the main text panel to have a white background and the total outside the also be white but just look like its all white without the grey border. Here is our site: http://www.aclandhomes.co.uk/ I hope this makes sense. I don't know if i can turn the grey border to white or even make the page content extend out to the full browser width?