title: Iterating over nodes and its childs and modify data
body: <p>I'm using Virtual Tree List for delphi 2009. I've created a tree with data such as:</p>
  
  <pre><code>type
    PTreeData = ^TTreeData;
    TTreeData = record
      FCaption: String;
      FPath: String;
    end;
  </code></pre>
  
  <p>I want to iterate over all elements but in specific order. I need to acquire first top level node, and then iterate over all of its children and modify <code>FPath</code> field. When I'm done with its children I want to get another top level node, and so on.</p>
  
  <p>First of all I don't know how to itterate over top level nodes. </p>
  
  <p>Thanks in advance for any tips on this</p>