function BinaryTree(key) {

var Node = function(key) {

this.key = key;

this.left = null;

this.righr = null;

};

var root = null;

var insertNode = function(node,newNode) {

if (newNode.key < node.key) { 

if (node.left === null) {

node.left = newNode; 

} else {

insertNode(node.left,newNode); 

}

} else{

if (node.right ===null) {

node.right = newNode;

} else {

insertNode(node.right,newNode);

}

}

}

this.insert = function(key) {

var newNode = new Node(key);

if (root === null) {

root = newNode;

} else {

insertNode(root,newNode); 

}

};

}

var nodes = [8,3,10,1,6,14,4,7,13];

var binaryTree = new BinaryTree(); 

        nodes.forEach(function(key) {

            binaryTree.insert(key);

        });