function Node(data, left, right) {
            this.data = data;
            this.left = left;
            this.right = right;
        }

        Node.prototype = {
            show: function () {
                console.log(this.data);
            }
        }

        function Tree() {
            this.root = null;
        }

        Tree.prototype = {
            insert: function (data) {
                var node = new Node(data, null, null);
                if (!this.root) {
                    this.root = node;
                    return;
                }
                var current = this.root;
                var parent = null;
                while (current) {
                    parent = current;
                    if (data < parent.data) {
                        current = current.left;
                        if (!current) {
                            parent.left = node;
                            return;
                        }
                    } else {
                        current = current.right;
                        if (!current) {
                            parent.right = node;
                            return;
                        }
                    }

                }
            },
            preOrder: function (node) {
                if (node) {
                    node.show();
                    this.preOrder(node.left);
                    this.preOrder(node.right);
                }
            },
            middleOrder: function (node) {
                if (node) {
                    this.middleOrder(node.left);
                    node.show();
                    this.