images = new Array(5);
images[0] = "<img src='images/home_pic1.png' />";
images[1] = "<img src='images/home_pic2.png' />";
images[2] = "<img src='images/home_pic3.png' />";
images[3] = "<img src='images/home_pic4.png' />";
images[4] = "<img src='images/home_pic5.png' />";
index = Math.floor(Math.random() * images.length);
document.write(images[index]);