function image() {
};

image = new image();
number = 0;

// imageArray
image[number++] = "<img src='images/pic1.jpg' border='0' alt='York Guildhall by Night'>"
image[number++] = "<img src='images/pic2.jpg' border='0' alt='York Minster'>"
image[number++] = "<img src='images/pic3.jpg' border='0' alt='York Boat Tours'>"
image[number++] = "<img src='images/pic4.jpg' border='0' alt='York Bar Walls'>"
image[number++] = "<img src='images/pic5.jpg' border='0' alt='Cliffords Tower York'>"
image[number++] = "<img src='images/pic6.jpg' border='0' alt='York Races'>"
image[number++] = "<img src='images/pic7.jpg' border='0' alt='Olgas Guesthouse'>"
image[number++] = "<img src='images/pic8.jpg' border='0' alt='Four Poster Room'>"
image[number++] = "<img src='images/pic9.jpg' border='0' alt='Twin Room'>"
image[number++] = "<img src='images/pic10.jpg' border='0' alt='Dining Room'>"
// keep adding items here...

increment = Math.floor(Math.random() * number);

document.write(image[increment]);