public BTnode postOrderTraversal(BTnode root)
	{
	
		BTnode left, right;
		
		if(root == null)
			return null;
		
		if(root.left == null && root.right == null)
			return root;
				
		left  = postOrderTraversal(root.left);
		right = postOrderTraversal(root.right);
		
		//if(right != null)
		//{
			//for(;right.left != null; right = right.left);
			
			
		//}
		
		if(left != null && right != null)
		{
			 right.right = root;
			 root.left = right;
			 root.right = null;
			 for(;right.left != null; right = right.left);
			 left.right = right;
			 right.left = left;
			 //for(;right.right!=null; right=right.right);
			 
			 return root;
		}
		
		/*if(left == null && right != null)
		{
			right.left = left;
			for(;right.right!=null; right=right.right);
			//System.out.println("for2 done");
			right.right = root;
			return root;
		}
		
		if(left != null && right == null)
		{
			left.right = root;
			root.left = left;
			return root;
		}*/
		
		return null;
	}