function image() {
};

image = new image();
number = 0;

// imageArray
image[number++] = "<img src='p7theme/001.jpg' border='0'>"
image[number++] = "<img src='p7theme/002.jpg' border='0'>"
image[number++] = "<img src='p7theme/003.jpg' border='0'>"
image[number++] = "<img src='p7theme/004.jpg' border='0'>"
image[number++] = "<img src='p7theme/005.jpg' border='0'>"
image[number++] = "<img src='p7theme/006.jpg' border='0'>"
image[number++] = "<img src='p7theme/007.jpg' border='0'>"
image[number++] = "<img src='p7theme/008.jpg' border='0'>"
image[number++] = "<img src='p7theme/009.jpg' border='0'>"
// keep adding items here...

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

document.write(image[increment]);