Help with Randomly loading pictures

Hello there, I need some help with making it so each time you refresh a page somewhere in that page there is an image when will randomly load 1 / 20 when you refresh, you’re great people if you help!

You can use some javascript:

<script type="text/javascript">
	var pictures_array = new Array("bug","house","me_and_mygirl");//add all your images here
	var index = Math.floor(Math.random()*pictures_array.length);
	document.write("<img src='"+pictures_array[index]+".jpg'>");
</script>