html background image fit to screen

1html {
2    height: 100%
3}
4body {
5    background-image:url("../images/myImage.jpg");
6    background-repeat: no-repeat;
7    background-size: 100% 100%;
8}

1body {
2  background-position: center;
3  background-repeat: no-repeat;
4  background-size: cover;
5}

1html {
2    height: 100%;
3}
4body {
5    color: #999;
6    background: url('../images/background/main_bg.jpg') no-repeat center center fixed;
7    font-family: 'Roboto', sans-serif;
8    -webkit-background-size: cover;
9    -moz-background-size: cover;
10    -o-background-size: cover;
11    background-size: cover;
12}

1body {
2  background-position: center;
3  background-repeat: no-repeat;
4  background-size: contain;
5}