HTML background image tiling problem_html/css_WEB-ITnose

There is a horizontal tile at the top of the web page, which covers the background image of the entire page. The setting is width:100%. After loading, it looks complete, but if the page has a horizontal scroll bar, drag the scroll bar to the right, and you will find that the images in the hidden part of the page are not tiled and are blank.
How to solve this problem?
[img=https://skydrive.live.com/embed?cid=DE243E377F0EED78&resid=DE243E377F0EED78!334&authkey=AEeWYD4H18yrUBs][/img]

Reply to discussion (solution)

Where is your background image placed? Is it body or div?

Where is your background image placed? Is it body or div?
Is it inside a div?

#top_bg { width: 100%; height: 147px; background: url( '../img/topbg.gif' ) repeat-x; margin:auto; }

Please think more before asking questions in the future! A very simple problem is to add a background image to the elements with a fixed width, so that a similar situation will not occur.