Here is a recipe for changing the width of the whole page of a fixed-width layout, using the CSS Properties pane:
- Click anywhere in your page. For this property, you must be on your DWT page.
- Look near the upper left for the "CSS Properties" tab. If instead you see "Folder List" or "Tag Properties", then you may use the small black triangles ( <| |> ) by those tabs to locate the desired tab. Or, menu "Format / CSS Properties..."
- Now in the "breadcrumbs" at the top of the page (<body> <div#container> ...), click on <div#container>. (If it is greyed out / you are unable to click on it, that means that you are on an HTML page which uses a DWT, and that the DWT is where the <div#container> must be set. You can find that DWT by: menu "Format / Dynamic Web Templates / Open Attached Dynamic Web Template".
- The CSS Properties pane is divided into sections, starting with [-] Font. Scroll down to section [-] Position. Locate item "width". My default fixed-width DWTs have a width of "790px" [pixels].
- Click in that area and either type a new value (be sure not to lose the "px"), or use the down-triangle that appears to select "Pick Length...", which gives a dialog box where you can type in the number by itself (so don't have to worry about messing up the "px").
- NOTE: You can easily convert this from a fixed-width to a flexible-width layout. Simply delete the width's value. Or replace it with "100%".