title: GroupBy without LINQ
body: <p>I am trying to achieve the following without LINQ:</p>
  
  <p>I have a list of CenterDetail objects (with CenterID and AreaID as property):</p>
  
  <ul>
  <li>objCenterDetail1 (CenterID=1, AreaID=1)</li>
  <li>objCenterDetail2 (CenterID=2, AreaID=1)</li>
  <li>objCenterDetail3 (CenterID=3, AreaID=1)</li>
  <li>objCenterDetail4 (CenterID=5, AreaID=2)</li>
  <li>objCenterDetail5 (CenterID=6, AreaID=2)</li>
  </ul>
  
  <p>I want to create an AreasDictionary as follows:</p>
  
  <ul>
  <li>AreaID=1: objCenterDetail1, objCenterDetail2, objCenterDetail3 </li>
  <li>AreaID=2: objCenterDetail4, objCenterDetail5 </li>
  </ul>
  
  <p>What is the best solution for this in C# with .NET 2.0?</p>