body, html {
          height: 100%;
        }
        .bg {
          /* The image used */
          background-image: url("images/back1.png");

          /* Half height */
          height: 100%;

          /* Center and scale the image nicely */
          background-position: center;
          background-repeat: no-repeat;
          background-size: cover;
        }

     body {
          /* The image used */
          background-image: url("images/back.png");

          /* Half height */
          height: 100%;

          /* Center and scale the image nicely */
          background-position: center;
          background-repeat: no-repeat;
          background-size: cover;
        }