Help with a binary tree

Question

I'm writing a binary tree class and am having some trouble with the Insert function. Here is the code for the TreeNode class...
public class TreeNode
     TreeNode Left;
     TreeNode Right;
     String Name;
     public TreeNode(String NodeName)
          Left = null;
          Right = null;
          Name = NodeName;
}And this is the code for the Tree class...
public class Tree
     TreeNode Root;
     public Tree(String RootNode)
          Root = new TreeNode(RootNode);
     public void Insert(String Name)
          InsertNode(Root, Name);
     public void InsertNode(TreeNode t, String NodeName)
          if (t == null)
               t = new TreeNode(NodeName);
          else
               if (NodeName.compareTo(t.Name) < 0)
                    InsertNode(t.Left, NodeName);
               else if (NodeName.compareTo(t.Name) > 0)
                    InsertNode(t.Right, NodeName);
               else if (NodeName.compareTo(t.Name) == 0)
                    System.out.println("Entered node that was already in Tree");
}When I enter a new node into a Tree containing just the root, it follows the recursion through once, then creates the new TreeNode as it should. However, the new node is not really recognized by the tree because when I try to insert another node, it only finds the root in the tree and only goes through one recursion. What's wrong?

Answer 1

I believe t.Left (or t.Right) is getting set in the line
t = new TreeNode(NodeName);
Since it is a recursive function, when it is called the second time, the "t" that is passed in is actually the original t.left (I think), which is getting set then.