debug a height of node function in AVL Tree

Hey, I'm working on a project that requires me to build an AVL Tree. The problem I'm running into is that the function that is supposed to return the height isn't working properly. I have the entire code written and even a main function to check preorder, inorder, and postorder. The inorder is correct but the preorder and postorder are incorrect because AVL Tree balancing never takes place. That is because the height function isn't running properly! Can someone debug the height function by changing MINIMAL amount of lines!? MUST BE COMPLETED RIGHT NOW WITHIN 1-2 HOURS!