#all {
  width: 740px;
  height: 650px;
  margin-left: auto;
  margin-right: auto;
}

#header {
  background-color: #666666;
  text-align: center;
  float: left;
  width: 740px;
  clear: both;
}

#left {
  float: left;
  width: 250px;
  clear: left;
}

#right {
  float: left;
  width: 490px;
}

#footer {
  float: left;
  width: 740px;
  clear: both;
  text-align: center;
  background-color: #666666;
 }