=gradient-image($from: #fff, $to: #000, $url: "")
  background: url($url)
  background: url($url), -webkit-gradient(linear, left top, left bottom, from($from), to($to))
  background: url($url), -o-gradient(top, bottom, from($from), to($to))
  background: url($url), -moz-linear-gradient(top, $from, $to)
  background-repeat: no-repeat
  *background-color: $from