#LeftContent {
  width: 230px;
  float: left;
  padding-top: 10px;
}

#MainContent{
  margin-left: 235px;
  margin-right: 165px;
  padding-top: 10px;
  width: 550px;
}

#RightContent {
  width: 160px;
  float: right; 
  padding-top: 10px;
}