function image() {
};

image = new image();
number = 0;

// imageArray

image[number++] = "<img src='lugansk/lugansk03.jpg' width='398' height='285' border='0'>"
image[number++] = "<img src='lugansk/lugansk05.jpg' width='398' height='285' border='0'>"
image[number++] = "<img src='lugansk/lugansk06.jpg' width='398' height='285' border='0'>"
image[number++] = "<img src='lugansk/lugansk13.jpg' width='398' height='285' border='0'>"

// keep adding items here...

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

document.write(image[increment]);