background image width to full code example
Example 1: css background image size to fit screen
html {
height: 100%
}
body {
background-image:url("../images/myImage.jpg");
background-repeat: no-repeat;
background-size: 100% 100%;
}
Example 2: css background image size fit screen
html {
background: url(images/bg.jpg) no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}