function image() {
};

image = new image();
number = 0;

// imageArray
image[number++] = "<img src='images/our_people.gif' border='0'>"
image[number++] = "<img src='images/our_people1.gif' border='0'>"
image[number++] = "<img src='images/our_people2.gif' border='0'>"
image[number++] = "<img src='images/our_people3.gif' border='0'>"
image[number++] = "<img src='images/our_people4.gif' border='0'>"
// keep adding items here...

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

document.write(image[increment]);