This value tells browsers to make the image repeat across the page and down the page to produce a grid effect. Delete that statement if you don't want your GIF to create a tiled background.

How to Make a Block of HTML Text Appear in Front of Another. HTML div containers make it possible for you to add interesting special effects to Web pages on your business website. Divs, which act ...

Cick on Choose to accept the new background. If you want to add your own image as a background click on the plus sign as above, but use the Finder window that opens to locate your chosen image.