IMAGES = [IMAGE_DIR+"kokenClass.jpg", IMAGE_DIR+"reedClass1.jpg", 
          IMAGE_DIR+"nielsenOffice.jpg", 
          IMAGE_DIR+"csClass.jpg", IMAGE_DIR+"reedClass2.jpg", 
          IMAGE_DIR+"robot2.jpg", IMAGE_DIR+"lab.jpg",
          IMAGE_DIR+"gameFest1.jpg", IMAGE_DIR+"gameFest2.jpg",
	        IMAGE_DIR+"gameFest3.jpg", IMAGE_DIR+"contest1.jpg", 
          IMAGE_DIR+"contest2.jpg", IMAGE_DIR+"betty.jpg",
          IMAGE_DIR+"robot1.jpg", IMAGE_DIR+"mallenbyOffice.jpg"];

DELAY = 0;
REAL_DELAY = 4000;    	// DURATION in mSEC FOR EACH IMAGE
INDEX = Math.floor(Math.random()*IMAGES.length);        // INDEX OF FIRST IMAGE
DISPLAY = true;		// TRUE IF IMAGES ARE TURNED ON, ELSE FALSE

function ToggleAd() {
  DISPLAY = !DISPLAY;
  if (DISPLAY) {
    SwitchAd();
  }
}  
 
function SwitchAd() {
  if (DISPLAY) {
    INDEX = (INDEX+1)%IMAGES.length;
    document["Ad_Image"].src = IMAGES[INDEX];
	DELAY = REAL_DELAY;
  }
}