hrahimi270

function getViewPercentage(element) {
  const viewport = {
    top: window.pageYOffset,
    bottom: window.pageYOffset + window.innerHeight
  };

  const elementBoundingRect = element.getBoundingClientRect();
  const elementPos = {
    top: elementBoundingRect.y + window.pageYOffset,
    bottom: elementBoundingRect.y + elementBoundingRect.height + window.pageYOffset

hrahimi270

/* Polyfill indexOf. */
var indexOf;

if (typeof Array.prototype.indexOf === 'function') {
    indexOf = function (haystack, needle) {
        return haystack.indexOf(needle);
    };
} else {
    indexOf = function (haystack, needle) {
        var i = 0, length = haystack.length, idx = -1, found = false;

hrahimi270

"use strict";
// By Mahmoud Eskandari @ MIT license
function validateCard(card) {
  if (typeof card === 'undefined'
    || card === null
    || card.length !== 16) {
    return false;
  }
  let cardTotal = 0;
  for (let i = 0; i < 16; i += 1) {