var nick_images = new Array('bench','bin','box','cars','cone','doorman','drawing','gelespie','holloway','painted','road','shutter','step');
var number;

function getRandomImage() 
{
	number = Math.random();
	number = Math.round(number * 13);
		
	if (number == 0) {
		getRandomImage();
	}
	else {
		document.images["random_top"].src = "http://www.penguin.co.uk/static/packages/uk/articles/hornby/gifs/polar/" + nick_images[number-1] + ".gif";
		document.images["random_bottom"].src = "http://www.penguin.co.uk/static/packages/uk/articles/hornby/gifs/polar/" + nick_images[number-1] + "_1.gif";
	}
}