Event.observe(window, 'load', 
      function() 
      {
         Event.observe('all_link', 'click', show_all_links); 
         Event.observe('images_link', 'click', show_image_links); 
         Event.observe('video_link', 'click', show_video_links); 
         Event.observe('text_link', 'click', show_text_links);       
      }
   ); 
   

function hideNamed(hideName)
{
   var allElements = document.getElementsByName(hideName); 
   for (var x = 0; x < allElements.length; x++) 
   {
      Effect.Fade(allElements[x]); 
   }
}
function showNamed(showName)
{
   var allElements = document.getElementsByName(showName); 
   for (var x = 0; x < allElements.length; x++) 
   {
      Effect.Appear(allElements[x]); 
   }
}

function hide_all()
{
   hideNamed('video'); 
   hideNamed('image'); 
   hideNamed('text');    
}
function show_all_links()
{
   hide_all(); 
   setTimeout("showNamed('video')", Effect.DefaultOptions.duration*1000); 
   setTimeout("showNamed('image')", Effect.DefaultOptions.duration*1000); 
   setTimeout("showNamed('text')", Effect.DefaultOptions.duration*1000); 
}

   
function show_video_links()
{
   hide_all(); 
   setTimeout("showNamed('video')", Effect.DefaultOptions.duration*1000); 
}

function show_image_links()
{
   hide_all(); 
   setTimeout("showNamed('image')", Effect.DefaultOptions.duration*1000); 
}

function show_text_links()
{
   hide_all(); 
   setTimeout("showNamed('text')", Effect.DefaultOptions.duration*1000); 
}