var image = new Array(3);
image[0] = 'img/head1.jpg';
image[1] = 'img/head2.jpg';
image[2] = 'img/head3.jpg';
image[3] = 'img/head1.jpg';


function ranimage() {
  max = 3;
    return(image[Math.floor(Math.random()*max+1)]);
}