generate the same random number for 2 arrays in js function

Javascript :

    function itemNumber() {
      var arrayOne = new Array('first', 'second', third);
      var arrayTwo = new Array('1', '2', '3');
}

HTML:

<div id='items'>
   <h1 id='words'>first</h1>
   <h1 id='numbers'>1</h1>
</div>

I want when refreshed thinks to look like first 1 or second 2 or third 3. Not like first 3, second 1.