When using this code to insert 5, then 18, into a binary search tree, the data value 18 is placed as the left child of the root instead of the right child. The statement if data < node.val: (in the insertR method) doesn't seem to be working correctly. Can someone tell me what is wrong? Thanks.

```
class NODE:
def __init__(self, data):
self.val = data
self.leftChild = None
self.rightChild = None
class BST:
def __init__(self):
self.root = None
def insert(self,data):
if self.root is None:
self.root = NODE(data)
else:
self.insertR(self.root, data)
def insertR(self, node, data):
if data < node.val:
if node.leftChild == None:
node.leftChild = NODE(data)
else:
self.insertR(node.leftChild, data)
else:
if node.rightChild == None:
node.rightChild = NODE(data)
else:
self.insertR(node.rightChild, data)
```