var delay = 6000;
var start_frame = 0;
var pause = false;

function init() {
  var lis1;
  var lis2;
  var end_frame1;
  var end_frame2;


  if($('slide-images_top')) {
    lis1 = $$('#slide-images_top div.contentpart');
  } 
  
  if($('slide-images_middle')) {
    lis2 = $$('#slide-images_middle div.contentpart');
  }
  
  if((!lis1 || lis1.length < 1) && (!lis2 || lis2.length < 1)) {
    return false;
  }
  
  if(lis1 || lis1.length > 0) {
    for( i=0; i < lis1.length; i++){
      if(i!=0){
        lis1[i].style.display = 'none';
      }
    }
  end_frame1 = lis1.length -1;
  }

  if(lis2 || lis2.length > 0) {
    for( i=0; i < lis2.length; i++){
      if(i!=0){
        lis2[i].style.display = 'none';
      }
    }
  end_frame2 = lis2.length -1;
  }

  if(lis1 && lis1.length > 0) start_slideshow(start_frame, end_frame1, delay, lis1);  
  if(lis2 && lis2.length > 0) start_slideshow(start_frame, end_frame2, delay+3500, lis2);  
}

function start_slideshow(start_frame, end_frame, delay, lis) {
  setTimeout(fadeInOut(start_frame,start_frame,end_frame, delay, lis), delay);    
}

function stop_slideshow() {
  pause = true;
}

function restart_slideshow() {
  pause = false;
  if($('slide-images_top') && $('slide-images_middle')) {
    init();
  }
}

function fadeInOut(frame, start_frame, end_frame, delay, lis) {
  if(!pause) {
    return (function() {
      if(!pause) {
        Effect.Fade(lis[frame], {
          afterFinish: function() {
            if(!pause) {
              if (frame == end_frame) { frame = start_frame; } else { frame++; }
              lisAppear = lis[frame];
              Effect.Appear(lisAppear);
              setTimeout(fadeInOut(frame, start_frame, end_frame, delay,lis), delay+1850);
            }
          }
        })
      }
    })
  }
}

Event.observe(window, 'load', init, false);