How do you get this header?

[Mr.Pea]

Although I've made the graphics and banners, I can't seem to get a smooth and perfectly fit finish - I think I am missing something for the header code:

templatemonster.com/oscommerce-templates/11909.html

The blue banner of the girl reading the book fits perfectly aligned with all the other images and layout - is there some code that has to be implemented in the stylesheet to create that finish.

Thus far, I am always finding my banners sit directly in the centre of the page (which is fine) but there's always excess room on either side of the image. When I inlarge the image, thinking I will be covering the "little gaps" on each side, it only pushes the page out farther, creating a horizontal scroll bar at the bottom of the browswer.

Does anyone know why it's doing this?

TIA

[kuroi]

There are numerous possible causes of this. Do you have a link at which it can be seen?