@Override
	public void startOutline () {
		// initialize the current node to the root node of the outline
		this.currentNode = tree.getRootNode();
		
		// clear out any existing children.
		while (currentNode.numOfChildren() > 0) {
			currentNode.removeChild(currentNode.getLastChild());
		} // end while
		
		// set the initial level to the root node's level
		currentLevel = -1 ;
		
	} // end startOutline