function start_slideshow(start_frame, end_frame, delay) {
    setTimeout(switch_slides(start_frame,start_frame,end_frame, delay), delay);
}
                        
function switch_slides(frame, start_frame, end_frame, delay) {
    return (function() {
        Effect.Fade('cross' + frame);
        if (frame == end_frame) { frame = start_frame; } else { frame = frame + 1; }
        setTimeout("Effect.Appear('cross" + frame + "');", 0);
        setTimeout(switch_slides(frame, start_frame, end_frame, delay), delay);
    })
}