tree.js

var nodo = function(value, left, right) {
     return {
       "value": value,
       "left": left,
       "right": right
     }
};

var tree = nodo(10,
      nodo(5, nodo(3, nodo(1), nodo(4)), nodo(7, undefined, nodo(9))),
      nodo(15, nodo(13, undefined, nodo(14)), nodo(16)));

function preOrder(node) {
   if (node == undefined)
      return;

   console.log(node.value);
   preOrder(node.left);
   preOrder(node.right);
}

preOrder(tree);