To change central dimension body

[ottone]

I use from little time OsCommerce but I succeeded already to create something of sufficient. I have however difficulty in the to resolve this problem: When I change the side columns (dx and sx) from 125px (default) to 200 px the page goes out outside from the screen. Obviously it is necessary to change and to reduce, I believe, the central body: how it is done? I did not find where to change it. Someone it can say me how to do.

Thanks

I excuse myself by mistake of English but this page was translated automatic with: Free Translation