banner image size and spacing, empty menu box

Hey, for my website at http://geborgen-wachsen.de I am currently not able to achieve the following changes: 1. make the header banner appear with the same width as the body of the page (I assume 978px) 2. remove the space on top and below the header banner 3. remove the unnecessary white space box in the header menu. Help would be much appreciated. Thanks for the wonderfull work, l.