Answers for "background images with format"

add background image in css

.w {
background-image: url("images/tom1.png");
}

.a {
background-image: url("images/tom2.png");
}

.s {
background-image: url("images/tom3.png");
}

background-image url( background.png )

body {
  /* Base64 encoded transparent gif */
  background: url(data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7);
}