OK, I'll try again
// creating node
TreeNode node = new TreeNode();
node.Key = \"nodeuniquekey\";
node.Text = \"Text\";
// add root node to flytreeview 1
flytreeview1.Nodes.Add(node);
// lets create child node
TreeNode node2 = new TreeNode();
node2.Key = \"nodeuniquekey2\";
node2.Text = \"Text2\";
// add it as a child of parent (node)
node.Nodes.Add(node2);