Sample implementation of a stack in JavaScript.

stack-example.js

// see: http://jsfiddle.net/r5p9Lbj5/

function Node(value) {
  this.bottom = null;
  this.value = value;
}

function Stack() {
  this.top = null;
}

Stack.prototype.push = function(value) {
  var newTop = new Node(value);
  newTop.bottom = this.top;
  this.top = newTop;
};

Stack.prototype.pop = function() {
  var oldTop = this.top;
  this.top = oldTop.bottom;
  return oldTop.value;
};

Stack.prototype.isEmpty = function() {
  return this.top == null;
};

var s = new Stack();
s.push(1);
s.push(5);
s.push('derp');

alert(s.pop());
alert(s.pop());
alert(s.pop());