void printZigZagBT(BTnode root)
	{
		BTnode tmpNode;
		Stack<BTnode> tmpStack;
		if(root == null)
			return;
		
		currentLevel.push(root);
		
		while(!currentLevel.empty())
		{
			tmpNode = currentLevel.pop();
			
			if(tmpNode != null)
			{
				if(leftToRight){
					System.out.println(tmpNode.data);
					nextLevel.add(tmpNode.left);
					nextLevel.add(tmpNode.right);
				}
				else
				{
					nextLevel.add(tmpNode.left);
					System.out.println(tmpNode.data);
					nextLevel.add(tmpNode.right);
				}
			}
			
			if(currentLevel.empty())
			{
				leftToRight = leftToRight ? false : true;
				tmpStack = currentLevel;
				currentLevel = nextLevel;
				nextLevel = tmpStack;
			}
		}
		
		
	}