a background image canot scale, it can only be set to repeat along the x, y or both axis.
instead of using one large div, you shlould break the page up into multiple divs and ablly the backgroung image to that way
Create one div for the head,another for content and another for footer.
It looks like you want the content to be white, so don't apply the background image there, but apply it to the header and footer.