#previous_button {
  position: absolute;
  background: transparent url(../images/main/our_philosophy/prev.gif) no-repeat 0 0;
  width: 50px;
  height: 475px;
  display: block;
  z-index: 200;
  left: 0;
  top: 0;
  cursor: pointer;
}
#previous_button.disabled {
  background: transparent !important;
  cursor: default !important;
}
#next_button {
  position: absolute;
  background: transparent url(../images/main/our_philosophy/next.gif) no-repeat 0 0;
  width: 50px;
  height: 475px;
  display: block;
  z-index: 500;
  left: 850px;
  top: 0;
  cursor: pointer;
}
#next_button.disabled {
  background: transparent !important;
  cursor: default !important;
}