function fade(obj1,obj2)
{
 new Effect.Parallel([
  new Effect.Fade(obj1,{duration:1,fps:25,sync:true}),
  new Effect.Opacity(obj2,{duration:0.5,fps:25,from:0.5,to:1.0,sync:true})
 ]);
}
function appear(obj1,obj2)
{
 new Effect.Parallel([
  new Effect.Appear(obj1,{duration:1,fps:25,from:0.0,to:1.0,sync:true}),
  new Effect.Opacity(obj2,{duration:0.5,fps:25,from:1.0,to:0.5,sync:true})
 ]);
}