#MainContent {
  margin: 0;
  float: left;
  width: 506px;
  /*border: 1px solid green;*/
}

#RightContent {
  width: 260px;
  float: right;
  min-height: 301px;
  /*border: 1px solid blue;*/
}

.contentGroup, .contentRegion {
  min-height: 301px;
}