var Movable = new Class({
  cont:null,
  fx:null,
  bound:null,
  src:null,
  dest:null,
  property:null,
  
  initialize:function(elt) {
    this.cont = elt;
  },
  
  open:function() {
     this.fx.start(this.property, this.dest);
	 this.is_open = true;
  },
  
  close:function() {
    this.fx.start(this.property, this.src);
	this.is_open = false;
  }
});