var chosenImage=new Array();
chosenImage[0]="randomjean.jpg";
chosenImage[1]="randomglenn.jpg";
chosenImage[2]="randomvicki.jpg";
chosenImage[3]="randombowl.jpg";

var getRan=Math.floor(Math.random()*chosenImage.length);

function randomImage()
{
document.getElementById('randomImage').setAttribute('src','artimages/random-images/'+chosenImage[getRan]);
}