var image1 = new Image();
image1.src = "images/but_video.jpg";
var image2 = new Image();
image2.src = "images/but_video_o.jpg";

var image3 = new Image();
image3.src = "images/but_bio.jpg";
var image4 = new Image();
image4.src = "images/but_bio_o.jpg";

var image5 = new Image();
image5.src = "images/but_contact.jpg";
var image6 = new Image();
image6.src = "images/but_contact_o.jpg";

var image7 = new Image();
image7.src = "images/but_blog.jpg";
var image8 = new Image();
image8.src = "images/but_blog_o.jpg";


var theImages = new Array()

theImages[0] = 'images/cont.jpg'
theImages[1] = 'images/cont2.jpg'
theImages[2] = 'images/cont3.jpg'
theImages[3] = 'images/cont4.jpg'
theImages[4] = 'images/cont5.jpg'


var j = 0
var p = theImages.length;
var preBuffer = new Array()
for (i = 0; i < p; i++){
   preBuffer[i] = new Image()
   preBuffer[i].src = theImages[i]
}
var whichImage = Math.round(Math.random()*(p-1));

function showImage(){
document.write('<img src="'+theImages[whichImage]+'">');
}

function roll(img_name, img_src) {
   document[img_name].src = img_src;
}