Find Value in Array

needle.js

var indexOf = function(needle) {
  if(typeof Array.prototype.indexOf === 'function') {
      indexOf = Array.prototype.indexOf;
  } else {
    indexOf = function(needle) {
      var i = -1,
          index = -1;
      for(i = 0; i < this.length; i++) {
          if(this[i] === needle) {
            index = i;
            break;
          }
      }
      return index;
    };
  }
  return indexOf.call(this, needle);
};