http://www.jeasyuicn.com/css-background-image-stretching.html

background-image:url(bg.png);

-moz-background-size: 100% 100%;

-o-background-size: 100% 100%;

-webkit-background-size: 100% 100%;

background-size: 100% 100%;

-moz-border-image: url(bg.png) 0;

background-repeat:no-repeat\9;

background-image:none\9;

filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='bg.png', sizingMethod='scale')\9;