function rand ( n )
{
  return ( Math.floor ( Math.random ( ) * n + 1 ) );
}


// Store some random image URL's

var random_images = new Array ( );
random_images[0] = "images/hp-header.jpg";
random_images[1] = "images/hp-header-blue.jpg";

// Pick a random image from the list,
// and set the image source to point to the image

function pick_image ( )
{
  document.getElementById("random-image").src = random_images[rand(2)-1];
}