javascript - random div on page load?

Hoping someone can help as I do not know much about JS

I have 3 divs

 <div id="content1">This is content 1 </div>
 <div id="content2">This is content 2 </div>
 <div id="content2">This is content 2 </div>

I require some JS that randomly loads one of those divs on page load and hide the other two

Any help would be much appreciated

Thanks